JP7685366B2 - smoke detector - Google Patents

Description

Application of Article 30, paragraph 2 of the Patent Act (1) Panasonic Corporation Life Solutions Company, April 16, 2021 (2) Toshiba Lighting & Technology Corporation, April 26, 2021 (3) Secom Co., Ltd., April 26, 2021 (4) SMB Building Materials Co., Ltd., May 13, 2021 (5) Emiya Area Partners Co., Ltd., April 28, 2021 (6) Kagoshima Electric Works Co., Ltd., May 14, 2021 (7) Sekisui Heim Supply Co., Ltd., April 22, 2021 (8) Sekisui Heim Industry Co., Ltd., April 23, 2021 (9) Hagihara Disaster Prevention, April 23, 2021 (10) Material Aid Co., Ltd., April 28, 2021 (11) Mitsuwa Denki Co., Ltd., April 26, 2021 (12) Mew House Engineering Co., Ltd., April 26, 2021 (13) Yamato Financial Co., Ltd., April 28, 2021 (14) Asahi Kasei Homes Co., Ltd., April 22, 2021 (15) Asahi Kasei Reform Co., Ltd., April 22, 2021 (16) Inoue Co., Ltd., May 7, 2021 (17) Inaba Denki Sangyo Co., Ltd., April 26, 2021 (18) Licom Co., Ltd., April 23, 2021 (19) Okayama Fire Prevention Center Co., Ltd., April 23, 2021 (20) Kibi Sogo Densetsu Co., Ltd., April 23, 2021 (21) Kodensha Co., Ltd., April 27, 2021 (22) Sarashina Seisakusho Co., Ltd., May 6, 2021 (23) Hanshin Bosai Equipment Co., Ltd., May 12, 2021 (24) NTT Facilities, Inc., May 14, 2021 (25) Okada Holdings Co., Ltd., April 28, 2021 (26) Kimura Co., Ltd., May 7, 2021 (27) House Depot Kanto Co., Ltd., April 26, 2021 (28) House Logicom Co., Ltd., April 26, 2021 (29) Livelife Co., Ltd., April 28, 2021 (30) World Co., Ltd., April 22, 2021 (31) Kyudenko Corporation, May 7, 2021 (32) Nippon Densho Co., Ltd., April 22, 2021 (33) Meirin Co., Ltd., May 7, 2021 (34) Kyushu Sekisui Heim Industry Co., Ltd., April 23, 2021 (35) Mitsui Home Components Co., Ltd., April 26, 2021 (36) Sanko Mokuzai Co., Ltd., May 6, 2021 (37) Sanshin Denzai Co., Ltd., May 11, 2021

Article 30, paragraph 2 of the Patent Act applies (preceding paragraph) (38) Mitsubishi Corporation Building Materials Co., Ltd., April 22, 2021 (39) Shikoku Nomi Co., Ltd., April 23, 2021 (40) Shiga Tokki Co., Ltd., May 11, 2021 (41) Sumitomo Forestry Co., Ltd., April 22, 2021 (42) Sumitomo Forestry Hometech Co., Ltd., April 22, 2021 (43) Kojima Electric Industry Co., Ltd., May 6, 2021 (44) Shinmei Denzai Co., Ltd., May 6, 2021 (45) Shoji Denki Co., Ltd., May 10, 2021 (46) Sekisui House Ltd., May 7, 2021 (47) Chiyoda Denzai Co., Ltd., April 26, 2021 (48) Obihiro Disaster Prevention System, May 13, 2021 (49) Yamato Living Co., Ltd., April 23, 2021 (50) Chugoku-Shikoku Sekisui Heim Industry Co., Ltd., May 7, 2021 (51) Chubu Home Service Co., Ltd., April 26, 2021 (52) Tsusho Co., Ltd., May 10, 2021 (53) Tanaka Shoji Co., Ltd., May 14, 2021 (54) Tohoku Sekisui Heim Industry Co., Ltd., April 22, 2021 (55) Nikko Electric Communication Co., Ltd., April 26, 2021 (56) Nissin Bosai Co., Ltd., May 7, 2021 (57) Nisshin Seisakusho Co., Ltd., April 27, 2021 (58) Nippon Densetsu Shizai Co., Ltd., April 23, 2021 (59) Hokkaido Sekisui Heim Industry Co., Ltd., May 7, 2021 (60) Hokkaido Fire Equipment Co., Ltd., April 23, 2021 (61) CS Disaster Prevention Kagoshima Co., Ltd., May 14, 2021 (62) Chikuho Tohatsu Shokai Co., Ltd., May 7, 2021 (63) Nakamura Disaster Prevention Co., Ltd., April 26, 2021 (64) Kansai Minamikyushusha Co., Ltd., April 28, 2021 (65) Kagoshima Electric Works Co., Ltd., May 7, 2021 (66) Crown Disaster Prevention Co., Ltd., May 14, 2021 (67) Japan Disaster Prevention Equipment Co., Ltd., April 16, 2021 (68) Central Disaster Prevention Co., Ltd., April 21, 2021 (69) Toshin Electric Co., Ltd., May 6, 2021 (70) Nishimura Co., Ltd., May 12, 2021 (71) Nittan Co., Ltd., April 22, 2021 (72) Yamato Protec Co., Ltd., April 27, 2021 (73) Kyokuyo Electric Co., Ltd., April 2, 2021 (74) Inaba Denki Sangyo Co., Ltd., May 7, 2021 (75) Okuyama Disaster Prevention Co., Ltd., May 6, 2021

Application of Article 30, Paragraph 2 of the Patent Act (Peck on the previous paragraph) (76) Okada Electric Industry Co., Ltd., May 13, 2021 (77) Okano Co., Ltd., May 12, 2021 (78) General Shokai Co., Ltd., May 12, 2021 (79) Minakami Co., Ltd., April 14, 2021 (80) Kyodensha Co., Ltd., May 10, 2021 (81) Kodensha Co., Ltd., May 10, 2021 (82) Yamamoto Shokai Co., Ltd., May 14, 2021 (83) Daikyo Disaster Prevention Co., Ltd., April 16, 2021 (84) Nippon Densho Co., Ltd., April 5, 2021 (85) Hokkaido Morita Co., Ltd., April 9, 2021 (86) F.S.K Kiso Disaster Prevention Equipment Co., Ltd., May 13, 2021 (87) Actus Equipment Co., Ltd., May 6, 2021 (88) Takeden Co., Ltd., April 27, 2021 (89) Prosus Co., Ltd., April 22, 2021 (90) World Co., Ltd., April 5, 2021 (91) Ogiko Electric Co., Ltd., April 9, 2021 (92) Hokuriku Denki Shokai Co., Ltd., May 7, 2021 (93) Kyushu Nomi Co., Ltd., April 2, 2021 (94) Shikoku Nomi Co., Ltd., April 2, 2021 (95) Shin-Etsu Shoji Co., Ltd., May 12, 2021 (96) Niigata Nomi Co., Ltd., May 11, 2021 (97) Sema Disaster Prevention Equipment Co., Ltd., May 7, 2021 (98) Chiba Nomi Co., Ltd., April 2, 2021 (99) Comprehensive Disaster Prevention Nakatech, May 6, 2021 (100) Omuro Disaster Prevention Co., Ltd., May 11, 2021 (101) Chuo Disaster Prevention System Co., Ltd., May 7, 2021 (102) Chuo Rika Kogyo Co., Ltd., April 21, 2021 (103) Chukyo Disaster Prevention Kogyo Co., Ltd., May 14, 2021 (104) Tanaka Shoji Co., Ltd., May 13, 2021 (105) Toho Disaster Prevention Industry Co., Ltd., April 8, 2021 (106) Nissho Sekisei Kogyo Co., Ltd., April 28, 2021 (107) Nissin Disaster Prevention Co., Ltd., May 7, 2021 (108) Hitachi Sogo Disaster Prevention Co., Ltd., May 12, 2021 (109) Fukushima Disaster Prevention Co., Ltd., May 7, 2021 (110) Toyota Disaster Prevention, May 7, 2021 (111) Hokkaido Dry Chemical Co., Ltd., April 15, 2021 (112) Ohashi Disaster Prevention Co., Ltd., May 10, 2021 (113) Miyazaki General Communication System Co., Ltd., May 7, 2021

The present invention relates to a smoke detector.

Scattered light type smoke detectors are known in the past (see, for example, Patent Document 1). Scattered light type smoke detectors generally include a dark box and a pair of light emitting and receiving elements. Smoke that enters the dark box scatters the light from the light emitting element, and the scattered light is received by the light receiving element to detect a fire.

JP 2019-175501 A

Insects such as spiders may invade such smoke detectors. If an insect invades a smoke detector and gets into the dark box, the insect may scatter the light from the light-emitting element, and the scattered light may be received by the light-receiving element. If the light-receiving element receives the light, a fire may be detected even though there is actually no fire. Another possibility is that the insect may prevent the light-emitting element from emitting light or the light-receiving element from receiving light, resulting in a fire not being detected even though there is actually a fire.

The present invention was made in consideration of these circumstances, and aims to reduce the possibility of false fire alarms or missed fire detections due to insect intrusion.

In order to solve the above problems, the smoke detector according to the present invention comprises a main body base plate and a substrate disposed below the main body base plate and substantially parallel to the main body base plate, the main body base plate being provided on the underside of the main body base plate and having a cylindrical wall that forms a smoke detection space, and a first rib that is connected at both ends to the outer surface of a first wall portion constituting the cylindrical wall and forms a light receiving unit storage space between the first wall portion and the first rib that extends from the underside of the main body base plate toward the substrate so as to prevent insects from entering the light receiving unit storage space, the substrate having an end that abuts or is close to the outer surface of the first wall portion and covers the light receiving unit storage space, and the substrate is equipped on its upper surface with a light emitting unit that irradiates light into the smoke detection space, and a light receiving unit that is housed in the light receiving unit storage space and receives light that is irradiated from the light emitting unit and scattered by smoke particles through a first light passing hole formed in the first wall portion.

The present invention can reduce the possibility of false fire alarms or missed fire detections due to insect intrusion.

Bottom view of smoke detector 100 Side view of smoke detector 100 Plan view of smoke detector 100 FIG. 1 is an exploded perspective view of a smoke detector 100. AA line cross-sectional view of FIG. Bottom view of main body base plate 1 1 is a bottom perspective view of the main body base plate 1. A perspective view of the bottom of the main body base plate 1 Bottom view of substrate 2 Plan view of substrate 2 A perspective view of the bottom surface of the substrate 2 A bottom view of the substrate 2 and the speaker 3 attached to the main body base plate 1. A side view of the substrate 2 and the speaker 3 attached to the main body base plate 1. FIG. 12 is an enlarged view of part B of FIG. Bottom view of middle plate 4 A perspective view of the bottom of the middle plate 4 Plan view of middle plate 4 A top perspective view of the middle plate 4 A bottom view of the middle plate 4 attached to the main body base plate 1. A side view of the middle plate 4 attached to the main body base plate 1. 20 is a cross-sectional view taken along line CC of FIG. FIG. 21 is an enlarged view of part D in FIG. Bottom view of the main body cover 5 Side view of the main body cover 5 Plan view of the main body cover 5 3. Cross-sectional view of line E-E in FIG. Bottom view of main body base plate 1A Top perspective view of the middle plate 4A A vertical cross-sectional view of the smoke detector 100A.

1. Embodiment 1-1. Configuration of the smoke detector 100 A smoke detector 100 according to one embodiment of the present invention will be described with reference to Figs. 1 to 5. Figs. 1 to 4 referred to in this description are a bottom view, a side view, a plan view, and an exploded perspective view of the smoke detector 100. Fig. 5 is a cross-sectional view taken along line A-A in Fig. 3.

As shown in these figures, particularly in Figures 4 and 5, the smoke detector 100 is composed of a circular main body base plate 1, a substantially L-shaped board 2 and a circular speaker 3 arranged substantially parallel below the main body base plate 1, a substantially circular middle plate 4 arranged substantially parallel below the board 2, and a cylindrical main body cover 5 with a bottom that is fixed to the main body base plate 1 while housing the main body base plate 1, board 2, speaker 3, and middle plate 4. Each of the components of the smoke detector 100 will be described in order below.

1-2. Configuration of main body base plate 1 First, the main body base plate 1 will be described with reference to Fig. 6 to Fig. 8. Fig. 6, which will be referred to in this description, is a bottom view of the main body base plate 1, and Figs. 7 and 8 are bottom perspective views from different viewpoints.

As shown in these figures, the main body base plate 1 has a battery accommodating section 101 formed from its center to its periphery. This battery accommodating section 101 is convex on the underside of the main body base plate 1 and concave on the upper side, and a cylindrical battery is accommodated in the concave on the upper side. The battery accommodated in this battery accommodating section 101 is connected to the board 2 and supplies power to the circuit on the board 2.

The main body base plate 1 also has a speaker housing 102 formed adjacent to the battery housing 101. This speaker housing 102 is a roughly C-shaped rib that protrudes vertically from the underside of the main body base plate 1. The speaker 3 is housed in this speaker housing 102.

The speaker housing 102 has a hook 1021 on its outer periphery. This hook 1021 is engaged with a locking hole 422 (see FIG. 18) in the middle plate 4, which will be described later.

The main body base plate 1 also has a cylindrical wall 103 formed on the axis of the battery housed in the battery housing section 101. This cylindrical wall 103 is an isosceles trapezoidal rib that protrudes vertically from the underside of the main body base plate 1. The lower end of this cylindrical wall 103 abuts against the upper surface of the middle plate 4, forming a smoke detection space.

The cylindrical wall 103 is composed of four linear wall sections 1031, 1032, 1033, and 1034. Of these, wall section 1033 has a light passing hole 1035 through which the light emitting section 205, described later, irradiates light into the smoke detection space. In addition, wall section 1034 has a light passing hole 1036 through which the light receiving section 206, described later, receives light from the smoke detection space.

The main body base plate 1 also has a generally U-shaped rib 104 with both ends connected to the outer surface of the wall portion 1033. This rib 104 forms a space for accommodating the light-emitting unit between itself and the wall portion 1033.

The rib 104 extends vertically from the underside of the main body base plate 1 toward the substrate 2 and abuts against the upper surface of the substrate 2 to prevent insects from entering the light-emitting unit housing space.

The main body base plate 1 also has a U-shaped rib 105 with both ends connected to the outer surface of the wall portion 1034. This rib 105 forms a space for accommodating the light receiving unit between itself and the wall portion 1034.

The rib 105 extends vertically from the underside of the main body base plate 1 toward the substrate 2 so as to prevent insects from entering the light receiving unit housing space. There is a small gap between the rib 105 and the substrate 2, but this gap is approximately the same size as the mesh of the insect screen ring 6 (see Figure 4) described below. In other words, it is of a size that prevents insects from passing through.

The main body base plate 1 also has a board attachment portion 106. This board attachment portion 106 is a rib that protrudes vertically from the underside of the main body base plate 1, and is formed to surround a roughly L-shaped area. The peripheral portion of the upper surface of the board 2 is attached to this board attachment portion 106.

This board mounting portion 106 has two hooks 1061 and 1062 on its outer surface. These two hooks 1061 and 1062 are respectively engaged with the engaging holes 423 and 424 (see FIG. 18) of the middle plate 4, which will be described later.

The main body base plate 1 also has two push-in sections 107A and 107B formed on the opposite side of the battery housing section 101 from the speaker housing section 102. These two push-in sections 107A and 107B are rod-shaped members, and are formed by forming a U-shaped through groove in the main body base plate 1.

Of the two push-in sections 107A and 107B, push-in section 107A is positioned so that it comes into contact with a registration switch 209, which will be described later, and when this push-in section 107A is pushed in by a user, the registration switch 209 is pressed. On the other hand, push-in section 107B is positioned so that it comes into contact with an erase switch 210, which will be described later, and when this push-in section 107B is pushed in by a user, the erase switch 210 is pressed.

The main body base plate 1 also has two columnar antenna holders 108 and 109 that protrude vertically from its periphery. Of these two antenna holders 108 and 109, the antenna holder 108 is disposed adjacent to the outer surface of the board mounting portion 106. This antenna holder 108 is inserted into an insertion hole 416 (see FIG. 15) in the middle plate 4, which will be described later. In addition, a U-shaped groove is formed at the tip of this antenna holder 108, and the antenna 212 is fitted into this groove.

On the other hand, the antenna holder 109 is disposed on the axis of the battery housed in the battery housing 101. This antenna holder 109 is inserted into a locking hole 425 (see FIG. 15) in the middle plate 4, which will be described later. In addition, a U-shaped groove is formed at the tip of this antenna holder 109, and the antenna 212 is fitted into this groove.

The antenna holder 109 also has a hook 1091 on its outer surface (in other words, the surface opposite to the surface facing the cylindrical wall 103). This hook 1091 is engaged with an engagement hole 425 (see FIG. 15) in the middle plate 4, which will be described later.

The main body base plate 1 also has a pair of plate-shaped switch holders 110 and 111 that protrude vertically from its periphery. These pair of switch holders 110 and 111 hold the lighted switch 8, which will be described later.

Of the pair of switch holding parts 110 and 111, switch holding part 110 has a U-shaped groove and a C-shaped groove formed at its tip. Of these grooves, the shaft of lighted switch 8 is fitted into the U-shaped groove, and antenna 212 is fitted into the C-shaped groove. On the other hand, switch holding part 111 has a U-shaped groove formed at its tip. The shaft of lighted switch 8 is fitted into this U-shaped groove.
The above is a description of the main body base plate 1.

1-3. Configuration of the substrate 2 Next, the substrate 2 will be described with reference to Fig. 9 to Fig. 11. Fig. 9 to Fig. 11, which will be referred to in this description, are a bottom view, a plan view, and a bottom perspective view of the substrate 2.

As shown in these figures, the substrate 2 has a sector-shaped cutout 201 with a central angle of approximately a right angle. The battery storage section 101 of the main body base plate 1 and the speaker 3 are placed in the area where this cutout 201 is formed. The speaker 3 placed in this area is connected to the substrate 2.

The substrate 2 also has an isosceles trapezoidal cutout 202. The cylindrical wall 103 of the main body base plate 1 is positioned in the area where the cutout 202 is formed.

The substrate 2 also has a pair of rectangular cutouts 203 and 204 that face each other across the isosceles trapezoidal cutout 202.

A light-emitting unit 205 is mounted on the upper surface of the substrate 2. This light-emitting unit 205 is, for example, a light-emitting diode. This light-emitting unit 205 is accommodated in a light-emitting unit accommodation space formed by the cylindrical wall 103 and ribs 104 of the main body base plate 1, and irradiates light into the smoke detection space formed by the cylindrical wall 103. At that time, the light-emitting unit 205 irradiates light into the smoke detection space through the light passage hole 1035 of the cylindrical wall 103.

A light receiving unit 206 is also mounted on the top surface of the substrate 2. This light receiving unit 206 is, for example, a photodiode housed in a shielding case. This light receiving unit 206 is housed in a light receiving unit housing space formed by the cylindrical wall 103 and ribs 105 of the main body base plate 1, and receives light from the light emitting unit 205 that is scattered when it hits smoke particles. At that time, the light receiving unit 206 receives the scattered light through the light passing hole 1036 of the cylindrical wall 103.

The light emitting unit 205 and the light receiving unit 206 are arranged along the isosceles trapezoidal cutout portion 202 so that their optical axes are not collinear.

The underside of the board 2 is also equipped with an inspection switch 207 and a confirmation light 208. Of these, the inspection switch 207 is a switch used to test the internal circuitry and battery life. This inspection switch 207 is designed to be pressed down when the illuminated switch 8, which will be described later, is pressed. On the other hand, the confirmation light 208 is an LED that notifies the results of the test.

The top surface of the substrate 2 is also equipped with a registration switch 209 and a deletion switch 210. The registration switch 209 is a switch used to set the wireless channel used by the smoke detector 100, and the deletion switch 210 is a switch used to delete the wireless channel setting.

A connector 211 is also mounted on the top surface of the substrate 2.

An antenna 212 made of a metal wire is also connected to the substrate 2. This antenna 212 is composed of a straight portion 2121 and an arc portion 2122. One end of the straight portion 2121 is connected to the wireless communication circuit 215 (not shown), extends vertically from the bottom surface of the substrate 2, and is inserted into the antenna hole 420 (see FIG. 15) of the middle plate 4. On the other hand, one end of the arc portion 2122 is connected to the other end of the straight portion 2121, and extends in an arc shape to surround the isosceles trapezoidal cutout portion 202.

A conductor 213 made of a metal wire is also connected to the substrate 2. This conductor 213 is composed of a straight portion 2131 and an arc portion 2132. One end of the straight portion 2131 is connected to a ground (not shown) on the substrate 2, and extends along the longitudinal direction of the battery accommodating section 101. On the other hand, one end of the arc portion 2132 is connected to the other end of the straight portion 2131, and extends in an arc shape to surround the speaker 3.

The board 2 also includes a control circuit 214 (not shown). This control circuit 214 executes the fire detection process, fire signal transmission process, and wireless channel setting process described below.

Furthermore, a wireless communication circuit 215 (not shown) is mounted on the board 2. This wireless communication circuit 215 uses the antenna 212 to perform wireless communication with other smoke detectors 100 and relay devices.
The above is the description of the substrate 2.

The peripheral portion of the upper surface of the substrate 2 described above is attached to the substrate attachment portion 106 of the main body base plate 1. The speaker 3 connected to the substrate 2 is fitted into the speaker housing portion 102 of the main body base plate 1. Figures 12 and 13 are bottom and side views of the substrate 2 and speaker 3 attached to the main body base plate 1 in this manner. Figure 14 is an enlarged view of part B in Figure 12.

As shown in FIG. 12 among these figures, the battery accommodating section 101 of the main body base plate 1 is disposed in the region where the fan-shaped cutout 201 of the substrate 2 is formed. Also, the cylindrical wall 103 of the main body base plate 1 is disposed in the region where the isosceles trapezoidal cutout 202 of the substrate 2 is formed. The cutout 202 of the substrate 2 abuts against the outer surface of this cylindrical wall 103.

More specifically, as shown in FIG. 14, the cutout 202 abuts against the outer surfaces of the walls 1031, 1033, and 1034 of the four walls 1031 to 1034 that constitute the cylindrical wall 103. Therefore, the substrate 2 covers the light-emitting unit accommodating space and the light-receiving unit accommodating space formed in the main body base plate 1. The rectangular cutout 203 of the substrate 2 forms a through hole 216 between the wall 1033. This through hole 216 is a through hole that connects the space between the substrate 2 and the middle plate 4 to the light-emitting unit accommodating space. The rectangular cutout 204 of the substrate 2 forms a through hole 217 between the wall 1034. This through hole 217 is a through hole that connects the space between the substrate 2 and the middle plate 4 to the light-receiving unit accommodating space.

Also, as shown in FIG. 12, the antenna 212 connected to the substrate 2 is sandwiched between the antenna holding parts 108 and 109 of the main body base plate 1 and the U-shaped groove formed at the tip of the switch holding part 110.

1-4. Configuration of the mid plate 4 Next, the mid plate 4 will be described with reference to Fig. 15 to Fig. 18. Fig. 15 to Fig. 18 referred to in this description are a bottom view, a bottom perspective view, a plan view, and a plan perspective view of the mid plate 4.

As shown in these figures, the middle plate 4 has a roughly U-shaped notch 401 formed from its center to its periphery. The battery storage section 101 of the main body base plate 1 is located in the area where this notch 401 is formed.

The middle plate 4 also has an elliptical ventilation hole 402 formed on the opposite side of the center from the notch 401. This ventilation hole 402 is a ventilation hole that connects the space between the middle plate 4 and the main body cover 5 to the smoke detection space formed in the main body base plate 1.

The middle plate 4 also has three labyrinth walls 403-405 formed around the vent hole 402. These three labyrinth walls 403-405 are plate-shaped walls that protrude vertically from the underside of the middle plate 4. These three labyrinth walls 403-405 are formed so as not to impede the inflow of smoke into the vent hole 402, but to impede the entry of external light into the vent hole 402.

The middle plate 4 also has a pair of rectangular locking holes 406 and 407 formed around the labyrinth walls 403 to 405. These pair of locking holes 406 and 407 are locking holes to which the hooks of the optical bench cover 7 (see FIG. 4), which will be described later, are locked.

The middle plate 4 also has eight antenna holders 408-415 formed radially around the labyrinth walls 403-405. These eight antenna holders 408-415 are generally linear plates that protrude vertically from the underside of the middle plate 4. These eight antenna holders 408-415 have notches at their tips, into which the antenna 212 is fitted.

The middle plate 4 also has a rectangular through hole 416 formed on its periphery. The antenna holder 108 of the main body base plate 1 is inserted through this through hole 416.

The middle plate 4 also has a number of speaker holes 417 formed adjacent to the U-shaped cutout 401. These speaker holes 417 are located below the speaker 3.

The middle plate 4 also has a switch hole 418 and an indicator hole 419 formed adjacent to the U-shaped cutout 401. Of these holes, the switch hole 418 is an insertion hole through which the inspection switch 207 is inserted. On the other hand, the indicator hole 419 is a light passing hole through which the light of the confirmation light 208 passes.

The middle plate 4 also has an antenna hole 420 formed in its periphery. This antenna hole 420 is an insertion hole through which the antenna 212 is inserted.

The middle plate 4 also has a side wall 421 erected on the periphery of its upper surface.

The middle plate 4 also has three rectangular locking holes 422-424 formed in the side wall 421. Of these three locking holes 422-424, the hook 1021 of the main body base plate 1 is locked into the locking hole 422, the hook 1061 of the main body base plate 1 is locked into the locking hole 423, and the hook 1062 of the main body base plate 1 is locked into the locking hole 424.

The middle plate 4 also has a locking hole 425 formed from its periphery to the side wall 421. As shown in FIG. 16, this locking hole 425 is arranged so as to sandwich the labyrinth wall 404 between it and the ventilation hole 402. This locking hole 425 is configured by connecting a rectangular hole formed in the periphery and a rectangular hole formed in the side wall 421. Of these holes, the antenna holder 109 of the main body base plate 1 is inserted into the former hole. Meanwhile, the hook 1091 of the main body base plate 1 is locked into the latter hole.

The middle plate 4 also has a partition 426 that separates the vent hole 402 and the locking hole 425, and both ends of the partition 426 are connected to the side walls 421. The partition 426 is a plate that protrudes vertically from the upper surface of the middle plate 4.

The middle plate 4 also has a pair of ribs 427 and 428 formed to surround the ventilation hole 402 together with the partition wall 426. The pair of ribs 427 and 428 are formed to extend substantially perpendicularly from the upper surface of the middle plate 4 toward the base plate 2. There is a small gap between the pair of ribs 427 and 428 and the base plate 2, but this gap is substantially the same size as the mesh of the insect screen ring 6 (see FIG. 4) described below. In other words, it is a size that prevents insects from passing through.

Of the pair of ribs 427 and 428, the rib 427 is composed of a straight portion 4271 having one end connected to the partition wall 426, a U-shaped portion 4272 having one end connected to the other end of the straight portion 4271, and a straight portion 4273 having one end connected to the other end of the U-shaped portion 4272. On the other hand, the rib 428 is composed of a straight portion 4281 having one end connected to the partition wall 426, and a U-shaped portion 4282 having one end connected to the other end of the straight portion 4281. The lower end of the cylindrical wall 103 of the main body base plate 1 is fitted into the space formed by the pair of ribs 427 and 428 and the partition wall 426.
The above is a description of the middle plate 4.

The middle plate 4 described above is attached to the main body base plate 1 so as to cover the substrate 2 and the speaker 3. At this time, the hooks 1021, 1061, 1062, and 1091 of the main body base plate 1 are engaged with the engagement holes 422 to 425 of the middle plate 4, thereby fixing the middle plate 4 to the main body base plate 1. Figures 19 and 20 are bottom and side views of the middle plate 4 thus attached to the main body base plate 1. Figure 21 is a cross-sectional view of line C-C in Figure 20. Figure 22 is an enlarged view of part D in Figure 21.

As shown in FIG. 19 among these figures, the battery storage section 101 of the main body base plate 1 is arranged in the area where the notch 401 of the middle plate 4 is formed. The antenna holder 108 of the main body base plate 1 is inserted into the insertion hole 416 of the middle plate 4. The antenna holder 109 of the main body base plate 1 is inserted into the locking hole 425 of the middle plate 4. The antenna 212 is inserted into the antenna hole 420 of the middle plate 4. The antenna 212 inserted into the antenna hole 420 is fitted into the notches of the antenna holders 408 to 415 of the middle plate 4. The inspection switch 207 is inserted into the switch hole 418 of the middle plate 4. The confirmation light 208 can be seen through the display hole 419 of the middle plate 4.

As shown in FIG. 22, the lower end of the cylindrical wall 103 of the main body base plate 1 is fitted into the space formed by the partition 426 of the middle plate 4 and the pair of ribs 427 and 428. As a result, the partition 426 of the middle plate 4 abuts against the outer surfaces of the walls 1032 to 1034 that constitute the cylindrical wall 103. The rib 427 of the middle plate 4 abuts against the outer surfaces of the walls 1031 and 1034 that constitute the cylindrical wall 103. In particular, the U-shaped portion 4272 of the rib 427 abuts against the outer surfaces of the walls 1034 at both ends and surrounds the through hole 217. In addition, the upper end of the U-shaped portion 4272 is close enough to the substrate 2 to prevent insects from passing through. Therefore, the U-shaped portion 4272 prevents insects from entering the through hole 217 in the space between the middle plate 4 and the substrate 2.

The rib 428 of the middle plate 4 abuts against the outer surface of the wall portion 1033 that constitutes the cylindrical wall 103. In particular, the U-shaped portion 4282 of the rib 428 abuts against the outer surface of the wall portion 1033 at both ends, surrounding the through hole 216. In addition, the upper end of this U-shaped portion 4282 is close enough to the base plate 2 to prevent insects from passing through. Therefore, this U-shaped portion 4282 prevents insects from entering the through hole 216 in the space between the middle plate 4 and the base plate 2.

1-5. Configuration of the body cover 5 Next, the body cover 5 will be described with reference to Figures 23 to 25. Figures 23 to 25 referred to in this description are bottom views, side views, and plan views of the body cover 5.

As shown in Fig. 23 among these figures, the main body cover 5 has an oval switch hole 501 formed in its bottom plate. The illuminated switch 8 (see Fig. 4) is fitted into this switch hole 501.

The main body cover 5 also has multiple ventilation holes 502 formed on the underside of its cylindrical portion, as shown in FIG. 24. These ventilation holes 502 are for allowing smoke to flow into the space between the main body cover 5 and the middle plate 4.

25, the body cover 5 has a pair of switch support portions 503A and 503B formed adjacent to the switch hole 501. The pair of switch support portions 503A and 503B have U-shaped cutout portions into which the shaft portion of the lighted switch 8 is fitted.
The above is a description of the main body cover 5.

The main body cover 5 described above is fixed to the main body base plate 1 while housing the main body base plate 1, the circuit board 2, the speaker 3 and the middle plate 4 (see FIG. 4). At this time, an insect screen ring 6 is attached to the middle plate 4 housed in the main body cover 5. More specifically, this insect screen ring 6 is attached so as to surround the ventilation hole 402 and the labyrinth walls 403-405 of the middle plate 4.

Then, an optical base cover 7 is attached so as to cover the lower opening of the attached insect screen ring 6. This optical base cover 7 has a disk portion, a star-shaped protrusion formed in the center of the upper surface of the disk portion, and a pair of hooks erected on the peripheral edge of the disk portion. When this optical base cover 7 is attached to the middle plate 4, the disk portion covers the lower opening of the insect screen ring 6, the protrusion is inserted between the labyrinth walls 403-405 of the middle plate 4, and the pair of hooks are engaged with a pair of engagement holes 406 and 407 of the middle plate 4.

In addition, an illuminated switch 8 is attached to the main body base plate 1 housed in the main body cover 5. This illuminated switch 8 has an oval plate portion, a protruding portion protruding vertically from one end of the plate portion, a columnar portion standing vertically on the other end of the plate portion, and a shaft portion formed at the base end of the columnar portion. This illuminated switch 8 is also made of a translucent resin material that contains a light diffusing material. When this illuminated switch 8 is attached to the main body base plate 1, its protruding portion abuts against the inspection switch 207 on the board 2, its columnar portion is inserted between the pair of switch holding portions 110 and 111 of the main body base plate 1, and its shaft portion is fitted into the U-shaped groove of the pair of switch holding portions 110 and 111.

As explained above, after the insect screen ring 6, optical base cover 7, and lighted switch 8 are attached, the main body cover 5 is attached to the main body base plate 1. When the main body cover 5 is attached to the main body base plate 1, the plate portion of the lighted switch 8 is fitted into the switch hole 501. In addition, the shaft portion of the lighted switch 8 is clamped between a pair of switch support portions 503A and 503B of the main body cover 5 and a pair of switch holding portions 110 and 111 of the main body base plate 1.

1-6. Function Next, the function of the rib 105 of the main body base plate 1 will be described.
As shown in Fig. 7, the rib 105 of the main body base plate 1 is a U-shaped rib whose both ends are connected to the outer surface of the cylindrical wall 103. In addition, as shown in Fig. 13, the lower end of this rib 105 is close enough to the substrate 2 to prevent insects from passing through. Therefore, this rib 105 prevents insects from entering the light receiving unit accommodating space formed between the rib and the cylindrical wall 103.

As described above, the main body base plate 1 has the push-in portions 107A and 107B (see FIG. 6). A U-shaped through groove is formed around these push-in portions 107A and 107B, and there is a possibility that an insect may enter the device through this U-shaped through groove. If an insect enters the device, the insect may move between the main body base plate 1 and the substrate 2 and reach the vicinity of the light receiving portion 206. At that time, assuming that there is no rib 105, the insect may enter the optical axis of the light receiving portion 206, preventing the light receiving portion 206 from receiving light. If the light receiving portion 206 is prevented from receiving light, even if a fire occurs, the fire cannot be detected. Another possibility is that the insect may enter the smoke detection space through the light passing hole 1036. If the insect enters the smoke detection space, the light of the light emitting portion 205 may hit the insect and scatter, and may be received by the light receiving portion 206. If the scattered light is received by the light receiving unit 206, a fire will be detected even if there is no actual fire.

In contrast, the rib 105 prevents insects from entering the light receiving unit housing space. This reduces the possibility of false fire alarms or missed fire detections caused by insect intrusion as described above.

Next, the function of the rib 427 of the mid-plate 4 will be described.
22, the rib 427 of the middle plate 4 has a U-shaped portion 4272. This U-shaped portion 4272 is a U-shaped rib whose both ends abut the outer surface of the cylindrical wall 103 and surround the through-hole 217. In addition, the upper end of this U-shaped portion 4272 is close enough to the base plate 2 to prevent insects from passing through. Therefore, this U-shaped portion 4272 prevents insects from entering the through-hole 217 in the space between the middle plate 4 and the base plate 2.

As described above, the main body cover 5 has the ventilation hole 502 (see FIG. 24). Also, as described above, the middle plate 4 has the display hole 419 (see FIG. 15). There is a possibility that insects may enter the space between the middle plate 4 and the substrate 2 through these ventilation holes 502 and the display hole 419. If an insect enters the space, it may move through the space and reach the vicinity of the through hole 217. At that time, assuming that the U-shaped portion 4272 does not exist, the insect may enter the light receiving unit housing space through the through hole 217. If the insect enters the light receiving unit housing space, it may prevent the light receiving unit 206 from receiving light. If the light receiving unit 206 is prevented from receiving light, even if a fire occurs, the fire cannot be detected. Another possibility is that the insect may enter the smoke detection space through the light passing hole 1036. If an insect enters the smoke detection space, the light from the light-emitting unit 205 may hit the insect, scatter, and be received by the light-receiving unit 206. If the scattered light is received by the light-receiving unit 206, a fire will be detected even if there is no actual fire.

In contrast, the presence of the U-shaped portion 4272 prevents insects from entering the through-hole 217. This reduces the possibility of false fire alarms or missed fire detections caused by insect intrusion as described above.

Next, the function of the rib 428 of the mid-plate 4 will be described.
22, the rib 428 of the middle plate 4 has a U-shaped portion 4282. This U-shaped portion 4282 is a U-shaped rib whose both ends abut the outer surface of the cylindrical wall 103 and surround the through-hole 216. In addition, the upper end of this U-shaped portion 4282 is close enough to the base plate 2 to prevent insects from passing through. Therefore, this U-shaped portion 4282 prevents insects from entering the through-hole 216 in the space between the middle plate 4 and the base plate 2.

As described above, the main body cover 5 has the ventilation hole 502 (see FIG. 24). Also, as described above, the middle plate 4 has the display hole 419 (see FIG. 15). There is a possibility that an insect may enter the space between the middle plate 4 and the substrate 2 through these ventilation holes 502 and display hole 419. If an insect enters the space, the insect may move through the space and reach the vicinity of the through hole 216. At that time, assuming that the U-shaped portion 4282 is not present, the insect may enter the light-emitting unit housing space through the through hole 216. If the insect enters the light-emitting unit housing space, the insect may prevent the light-emitting unit 205 from emitting light. If the light-emitting unit 205 is prevented from emitting light, even if a fire occurs, the fire cannot be detected. Another possibility is that the insect may enter the smoke detection space through the light passing hole 1035. If the insect enters the smoke detection space, the light of the light-emitting unit 205 may hit the insect and scatter, and may be received by the light-receiving unit 206. If the scattered light is received by the light receiving unit 206, a fire will be detected even if there is no actual fire.

In contrast, the presence of the U-shaped portion 4282 prevents insects from entering the through-hole 216. This reduces the possibility of false fire alarms or missed fire detections caused by insect intrusion as described above.

Next, the effect of forming a hook 1091 on the antenna holding portion 109 of the main body base plate 1 will be described with reference to FIG. 26. FIG. 26, which is referred to in this description, is a cross-sectional view taken along line E-E in FIG. 3. Note that hatching has been omitted in FIG. 26 to prevent the drawing from becoming difficult to see.

As shown in the figure, a cut-off hole 112 is formed directly above the hook 1091. This cut-off hole 112 is a hole that is formed when the main body base plate 1 is molded using a die. If an insect enters this cut-off hole 112, there is a possibility that the insect will pass between the inner circumferential surface of the main body cover 5 and the outer circumferential surface of the middle plate 4, as indicated by arrow A1 in the figure, and reach the space between the upper surface of the main body cover 5 and the lower surface of the middle plate 4. However, even if the insect does reach that space, it will be blocked by the insect screen ring 6 and will not be able to enter the smoke detection space.

In contrast to this, let us assume that a hook is formed on the cylindrical wall 103 instead of the antenna holding portion 109. More specifically, let us assume that a main body base plate 1A has a hook 1037 formed on the cylindrical wall 103. Figure 27 is a bottom view of this main body base plate 1A. In the main body base plate 1A shown in this figure, the hook 1037 is formed on the outer surface of the wall portion 1032 that constitutes the cylindrical wall 103.

Assuming that, in accordance with this change in the position of the hook, a locking hole is formed in the partition 426 instead of the side wall 421 of the middle plate 4. More specifically, assume that a middle plate 4A has a locking hole 4261 formed in the partition 426. Figure 28 is a top perspective view of this middle plate 4A. In the middle plate 4A shown in this figure, a locking hole 4261 is formed in the center of the partition 426. The hook 1037 is locked into this locking hole 4261.

Let us assume that the main body base plate 1A and middle plate 4A described above are replaced with the main body base plate 1 and middle plate 4. More specifically, let us assume that a smoke detector 100A is provided with the main body base plate 1A and middle plate 4A. Figure 29 is a vertical cross-sectional view of this smoke detector 100A. Note that hatching has been omitted in Figure 29 to prevent the drawing from becoming difficult to read.

In the smoke detector 100A shown in the figure, a cut-off hole 113 is formed directly above the hook 1037. This cut-off hole 113 is a hole formed when the main body base plate 1A is molded. If an insect enters this cut-off hole 113, the insect may pass between the partition wall 426 and the side wall 421 of the middle plate 4A, as shown by the arrow A2 in the figure, and enter the insect screen ring 6 through the cut-off hole 429 formed under the locking hole 4261. If the insect enters the insect screen ring 6, it may pass between the labyrinth walls 403-405, pass through the ventilation hole 402, and enter the smoke detection space. If the insect enters the smoke detection space, the light of the light-emitting unit 205 may hit the insect and scatter, and may be received by the light-receiving unit 206. If the scattered light is received by the light-receiving unit 206, a fire will be detected even though a fire does not actually occur. Another possibility is that an insect may enter the light-emitting unit housing space from the smoke detection space through light passing hole 1035. If the insect enters the light-emitting unit housing space, it may prevent the light-emitting unit 205 from emitting light, and even if a fire breaks out, the fire may not be detected. Yet another possibility is that an insect may enter the light-receiving unit housing space from the smoke detection space through light passing hole 1036. If the insect enters the light-receiving unit housing space, it may prevent the light-receiving unit 206 from receiving light, and even if a fire breaks out, the fire may not be detected.

In contrast, if a hook 1091 is formed on the antenna holding portion 109, the cut-off hole 112 directly above it will be located outside the insect screen ring 6 in a side view (see FIG. 26). Therefore, even if an insect does invade the cut-off hole 112, it will be difficult for it to get inside the insect screen ring 6. This reduces the possibility of false fire alarms or missed fire detection due to insect intrusion as described above.

1-7. Operation Next, a description will be given of the operation of the smoke detector 100. Specifically, a fire detection process, a fire signal transfer process, and a wireless channel setting process will be described.

First, the fire detection process will be described.
When a fire breaks out in the monitoring area of the smoke detector 100, the smoke from the fire rises toward the ceiling. When it reaches the ceiling, it flows horizontally along the ceiling surface. When the smoke flows in through the vent 502 of the smoke detector 100, it passes through the insect screen ring 6, passes through the vent 402 of the middle plate 4, and flows into the smoke detection space. When the smoke flows into the smoke detection space, the light of the light emitting unit 205 hits the smoke particles and is scattered, and is received by the light receiving unit 206. When the light receiving unit 206 receives the scattered light, it outputs a detection signal to the control circuit 214. When the control circuit 214 receives this detection signal, it causes the speaker 3 to emit an alarm sound, and causes the wireless communication circuit 215 to transmit a fire signal to other smoke detectors 100 and relay devices.
This concludes the description of the fire detection process.

Next, the fire signal transfer process will be described.
When the control circuit 214 of the smoke detector 100 receives a fire signal from another smoke detector 100, it causes the speaker 3 to emit an alarm sound. In addition, the control circuit 214 causes the wireless communication circuit 215 to transmit the fire signal to another smoke detector 100 or a relay device. This allows the smoke detectors 100 to be linked together.

Next, the wireless channel setting process will be described.
When the user presses and holds the registration switch 209 of the smoke detector 100, the control circuit 214 starts a wireless channel setting mode. In this wireless channel setting mode, the control circuit 214 changes the wireless channel each time the registration switch 209 is pressed for a short time. In addition, each time the wireless channel is changed, the control circuit 214 causes the speaker 3 to emit a guide voice notifying the user of the wireless channel number. When the registration switch 209 is pressed and held again, the control circuit 214 stores the number of the selected wireless channel and ends the wireless channel setting mode.

After that, when the user presses and holds the erase switch 210, the control circuit 214 erases the stored wireless channel number.

2. Modifications The above embodiment may be modified as follows. The following modifications may be combined with each other.

2-1. Modification 1
6 and the like is merely an example. The shape of the main body base plate 1 may be changed as appropriate depending on the shapes of the battery, the board 2, and the speaker 3 mounted in the smoke detector 100, the types of electronic components mounted on the board 2, and the like.

2-2. Modification 2
The cylindrical wall 103 of the main body base plate 1 has an isosceles trapezoidal shape as shown in Fig. 6. However, this shape is merely an example, and instead of the isosceles trapezoidal shape, for example, the shape may be a triangle.

2-3. Modification 3
The rib 104 of the main body base plate 1 has a substantially U-shape as shown in Fig. 6. However, this shape is merely an example, and instead of the substantially U-shape, for example, the rib may have a semicircular shape.

As described above, the rib 104 abuts against the substrate 2. However, it is not essential that the rib 104 abuts against the substrate 2. The rib 104 may not abut against the substrate 2, but may leave a small gap between them. However, the size of the gap must be such that it prevents insects from passing through. Specifically, for example, the size of the gap may be approximately the same as the size of the mesh of the insect screen ring 6.

2-4. Modification 4
The rib 105 of the main body base plate 1 has a U-shape as shown in Fig. 6. However, this shape is merely an example, and instead of the U-shape, for example, the rib may have a semicircular shape.

As described above, there is a small gap between the rib 105 and the substrate 2. However, this gap is not essential. The rib 105 may be abutted against the substrate 2 without leaving a gap between the rib 105 and the substrate 2.

2-5. Modification 5
9 and the like is merely an example. The shape of the substrate 2 may be changed as appropriate depending on the shape of the battery and speaker 3 mounted in the smoke detector 100, the shape of the cylindrical wall 103 of the main body base plate 1, and the like.

2-6. Modification 6
As described above, the notch 202 of the substrate 2 abuts against the outer surface of the cylindrical wall 103 of the main body base plate 1. However, it is not essential that the notch 202 abuts against the outer surface of the cylindrical wall 103. The notch 202 may be located close to the outer surface of the cylindrical wall 103 with a small gap between them, without abutting against the outer surface. However, the size of the gap in this case is set to be large enough to prevent insects from passing through. Specifically, for example, the size may be approximately the same as the size of the mesh of the insect screen ring 6.

The pair of cutouts 203 and 204 of the substrate 2 have a rectangular shape as shown in FIG. 14. However, this shape is merely an example, and instead of a rectangular shape, the cutouts may have, for example, a semicircular shape.

2-7. Modification 7
15 and the like is merely an example. The shape of the middle plate 4 may be changed as appropriate depending on the shapes of the battery, the board 2, and the speaker 3 mounted in the smoke detector 100, the types of electronic components mounted on the board 2, and the like.

2-8. Modification 8
The U-shaped portion 4272 of the rib 427 of the middle plate 4 has a U-shape as shown in Fig. 22. However, this shape is merely an example, and instead of the U-shape, for example, the U-shaped portion 4272 may have a semicircular shape.

As described above, there is a small gap between the rib 427 and the substrate 2. However, this gap is not essential. The rib 427 may be abutted against the substrate 2 without leaving a gap between the rib 427 and the substrate 2.

2-9. Modification 9
The U-shaped portion 4282 of the rib 428 of the middle plate 4 has a U-shape as shown in Fig. 22. However, this shape is merely an example, and instead of the U-shape, for example, the U-shaped portion 4282 may have a semicircular shape.

As described above, there is a small gap between the rib 428 and the substrate 2. However, this gap is not essential. The rib 428 may be abutted against the substrate 2 without leaving a gap between the rib 428 and the substrate 2.

2-10. Modification 10
The insect screen ring 6 has a cylindrical shape as shown in Fig. 4. However, this shape is merely an example, and the insect screen ring 6 may have, for example, an elliptical cylindrical shape or a square cylindrical shape instead of a cylindrical shape.

2-11. Modification 11
In order to reduce the possibility of false fire alarms or missed fire detections due to insect intrusion, the smoke detector 100 is provided with a rib 105 (see FIG. 6) on the main body base plate 1 and a pair of ribs 427 and 428 (see FIG. 17) on the middle plate 4. However, it is not essential for the smoke detector 100 to have all of these ribs. The smoke detector 100 may be provided with only one or two of these ribs.

1...Main body base plate, 2...Circuit board, 3...Speaker, 4...Middle plate, 5...Main body cover, 6...Insect screen ring, 7...Optical table cover, 8...Illuminated switch, 100...Smoke detector, 101...Battery storage section, 102...Speaker storage section, 103...Cylindrical wall, 104...Rib, 105...Rib, 106...Circuit board mounting section, 107A, 107B...Push-in section, 108, 109...Antenna holding section, 110, 111...Switch holding section, 201...Notch, 202...Notch, 203...Notch, 204...Notch, 205...Light-emitting section, 206...Light-receiving section, 207...Inspection switch, 208...Confirmation light, 209...Registration switch, 210...Erase switch, 211...Connector, 212...Antenna, 213...Conductor , 214...control circuit, 215...wireless communication circuit, 216...through hole, 217...through hole, 401...notch, 402...ventilation hole, 403-405...labyrinth wall, 406, 407...locking hole, 408-415...antenna holder, 416...insertion hole, 417...speaker hole, 418...switch hole, 419...display hole, 420...antenna hole , 421...side wall, 422-425...locking holes, 426...partition wall, 427, 428...rib, 501...switch hole, 502...ventilation hole, 503A, 503B...switch support part, 1031-1034...wall part, 1035, 1036...light passage hole, 2121...straight part, 2122...arc part, 2131...straight part, 2132...arc part

Claims (6)

A main body base plate,
a substrate disposed below the main body base plate and substantially parallel to the main body base plate,
The main body base plate is
A cylindrical wall is provided on the lower surface of the main body base plate and forms a smoke detection space;
a first rib, both ends of which are connected to an outer surface of a first wall portion constituting the cylindrical wall, forming a light receiving unit accommodating space between the first wall portion and the first rib, the first rib extending from a lower surface of the main body base plate toward the substrate so as to prevent insects from entering the light receiving unit accommodating space;
an end portion of the substrate abuts against or is adjacent to an outer surface of the first wall portion and covers the light receiving portion accommodating space;
A light-emitting unit that irradiates light into the smoke detection space and a light-receiving unit that is accommodated in the light-receiving unit accommodating space and receives light that is irradiated from the light-emitting unit and hits smoke particles and scattered, through a first light passing hole formed in the first wall portion, are mounted on an upper surface of the substrate; and
The gap between the first rib and the substrate has a size that prevents the insects from passing through.
A smoke detector characterized by: A main body base plate,
a substrate disposed under the main body base plate and substantially parallel to the main body base plate;
Equipped with
The main body base plate is
A cylindrical wall is provided on the lower surface of the main body base plate and forms a smoke detection space;
a first rib, both ends of which are connected to an outer surface of a first wall portion constituting the cylindrical wall and which forms a light receiving unit accommodating space between the first wall portion and the first rib, the first rib extending from a lower surface of the main body base plate toward the substrate so as to prevent insects from entering the light receiving unit accommodating space;
having
an end portion of the substrate abuts against or is adjacent to an outer surface of the first wall portion and covers the light receiving portion accommodating space;
A light-emitting unit that irradiates light into the smoke detection space and a light-receiving unit that is accommodated in the light-receiving unit accommodating space and receives light that is irradiated from the light-emitting unit and hits smoke particles and scattered, through a first light passing hole formed in the first wall portion, are mounted on an upper surface of the substrate; and
a mid-plate disposed below the base plate and generally parallel to the base plate;
the substrate has a first cutout portion that forms a first through hole between the substrate and an outer surface of the first wall portion,
The smoke detector is characterized in that the middle plate has a second rib, both ends of which abut against the outer surface of the first wall portion and which surrounds the first through hole, the second rib extending from the upper surface of the middle plate toward the base plate so as to prevent insects from entering the first through hole. the main body base plate further includes a third rib, both ends of which are connected to an outer surface of a second wall portion constituting the cylindrical wall, forming a light-emitting unit accommodating space between the main body base plate and the second wall portion, the third rib extending from a lower surface of the main body base plate toward the substrate so as to prevent insects from entering the light-emitting unit accommodating space;
an end portion of the substrate abuts against or is close to an outer surface of the second wall portion and covers the light-emitting portion accommodating space;
the substrate further has a second cutout portion that forms a second through hole between the second cutout portion and an outer surface of the second wall portion,
the light emitting unit is accommodated in the light emitting unit accommodating space and irradiates light into the smoke detection space through a second light passing hole formed in the second wall portion;
3. The smoke detector of claim 2, further comprising a fourth rib, the second wall portion having both ends abutting the outer surface of the second wall portion, surrounding the second through hole, the fourth rib extending from the upper surface of the mid plate toward the base plate so as to prevent insects from entering the second through hole. The middle plate further has a vent hole for allowing smoke to flow into the smoke detection space,
The device further includes a cylindrical insect screen disposed on the lower surface of the middle plate so as to surround the ventilation hole,
The main body base plate further has a hook provided on its lower surface at a position outside the insect screen in a side view,
The smoke detector according to claim 2 or 3, wherein the middle plate further has a locking hole provided on an upper surface thereof, into which the hook is locked. A main body base plate,
A substrate disposed under the main body base plate and substantially parallel to the main body base plate;
a middle plate disposed below the base plate and substantially parallel to the base plate,
The main body base plate is
A cylindrical wall is provided on the lower surface of the main body base plate and forms a smoke detection space;
a first rib, both ends of which are connected to an outer surface of a wall portion constituting the cylindrical wall, and which forms a light-emitting unit accommodating space between the wall portion and the first rib;
an end portion of the substrate abuts against or is close to an outer surface of the wall portion and covers the light-emitting portion accommodating space;
A light emitting unit is mounted on the upper surface of the substrate, the light emitting unit being accommodated in the light emitting unit accommodation space and irradiating light into the smoke detection space through a light passing hole formed in the wall portion, and a light receiving unit is mounted on the upper surface of the substrate and receiving light scattered by the light emitting unit when the light hits smoke particles,
the substrate has a notch that forms a through hole between the substrate and an outer surface of the wall portion,
The smoke detector is characterized in that the middle plate has a second rib, both ends of which abut against the outer surface of the wall portion and which surrounds the through hole and extends from the upper surface of the middle plate toward the base plate so as to prevent insects from entering the through hole. A main body base plate having a cylindrical wall on its lower surface that forms a smoke detection space;
A substrate disposed under the main body base plate and substantially parallel to the main body base plate;
a middle plate disposed under the base plate and substantially parallel to the base plate, the middle plate having an air hole for allowing smoke to flow into the smoke detection space;
a cylindrical insect screen disposed on the lower surface of the middle plate so as to surround the ventilation hole;
The main body base plate further has a hook provided on its lower surface at a position outside the insect screen in a side view,
A light-emitting unit that irradiates light into the smoke detection space and a light-receiving unit that receives light that is irradiated from the light-emitting unit and hits smoke particles and scattered thereon are mounted on an upper surface of the substrate,
The smoke detector, wherein the middle plate further has a locking hole provided on an upper surface thereof, into which the hook is locked.