JP7213026B2 - smoke detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a smoke sensor, and more particularly to a smoke sensor that optically detects light scattered by smoke.

In this specification, the vertical direction represents the space in which the smoke detector should be detected, for example, the direction in which it is mounted on the ceiling in a room of a building, and when it is the vertical direction in a specific drawing states that. Each component of the smoke detector is shown in the same orientation as the front, rear, left and right sides, top, and bottom of the smoke detector when mounted on the ceiling.

2. Description of the Related Art Conventionally, in a photoelectric sensor, smoke is detected by detecting light emitted from a light-emitting element and scattered by smoke with a light-receiving element. In this configuration, there is a problem that if ambient light (that is, light from the installation space) enters the detection space, it will be erroneously detected as the presence of smoke.

A labyrinth wall (light-shielding wall) that prevents ambient light from entering and allows smoke to flow in has been installed (Patent Document 1). However, the structure is complicated in order to achieve good inflow characteristics while preventing intrusion of ambient light.

JP 2007-13212

SUMMARY OF THE INVENTION It is an object of the present invention to provide a smoke sensor that achieves good inflow characteristics while preventing the intrusion of ambient light.

In the following description, descriptions in embodiments of the invention to be described later are indicated by figures and paragraph numbers in parentheses ( ).
The present invention
A blower 100 provided in the housing 3 sucks ambient air from an upper or upper side air intake port 11 , passes the air passage, and discharges the sucked air from a lower or lower side air outlet 24 ,
A fire detection means for detecting a fire by the sucked air,
A light-blocking smoke detection space 45 is formed in the middle of the air passage downstream of the blower 100 (paragraphs [0027, 0029]), and a smoke detection area 111 (FIG. 22) is provided in the smoke detection space 45,
At least one of the passage from the intake port 11 to the smoke detection region 111 and the passage from the smoke detection region 111 to the exhaust port 24 is bent in at least three axial directions along the air flow direction,
a light emitting element 112 that emits light toward the smoke detection area 111;
a light receiving element 113 having an optical axis that intersects the optical axis of the light emitting element 112 in the smoke detection area 111;
It extends along the optical axis of the light receiving element 113 to the side opposite to the light receiving element 113 with respect to the smoke detection area 111 , opens to face the smoke detection area 111 , and closes at a position away from the smoke detection area 111 . and a light shielding member 118 having a light shielding space 121 corresponding to the directional characteristics around the optical axis,
The fire detection means is
a processing circuit 62;
a temperature detection element 127 (FIG. 19) provided in the air passage 32 upstream of the blower 100 (paragraphs [0027, 0028, 0078]);
A display element 92 that performs a display operation representing the occurrence of a fire,
The processing circuitry 62
The light-emitting element 112 is turned on every predetermined set time W0 to capture the light receiving signal from the light-receiving element 113, and then the light-emitting element 112 is turned off (paragraph [0050]),
In response to the light receiving signal from the light receiving element 113, when the concentration of smoke in the air is equal to or higher than the predetermined value L1, the display element 92 is driven (paragraph [0051]),
When the temperature of the air detected by the temperature detection element 127 reaches or exceeds a predetermined temperature at the time of fire, the display element 92 is driven regardless of the density of the smoke (paragraph [0054]). Fire and smoke detectors.

Also, by not providing a light-shielding wall having a complicated structure, design and manufacturing are facilitated, and cost reduction can be expected.

The present invention
The detection means for detecting fire is characterized by having a plurality of fire detection means.

Smoke and heat generated by a fire have the characteristic of rising from the point of origin, and after moving up to the ceiling position, move along the ceiling. In the conventional technology, the air intake is located below the center of the detector, so after smoke or heat reaches the low air intake away from the ceiling, the smoke or heat flows into the detector, causing a fire. In order to detect a fire, the problem is that it takes time to detect smoke even after it reaches the area around the detector. need to improve.

In the present invention, a fire can be quickly and reliably detected by providing an intake port on the upper side or the upper side of the sensor and an exhaust port on the lower side or the lower side of the sensor with a built-in blower. becomes possible. For example, by providing the air intake near the ceiling, it is possible to quickly and reliably guide the smoke moving along the ceiling to the detection area.

In conventional smoke detectors, the upper part of a body that extends vertically is fixed to the ceiling, and smoke naturally flows from below the body and enters. The smoke rises in the body through labyrinth walls, which are circularly arranged in a horizontal plane, and reaches the light emitting/receiving part of the optical element, where the smoke remains. Therefore, after the smoke is generated, it follows its natural convection and reaches the light emitting/receiving part of the optical element, so it takes a relatively long time until the smoke is detected. The labyrinth walls also lengthen the travel path of the smoke, which also causes the smoke to take a relatively long time to be detected.

This conventional smoke sensor has a complicated structure for preventing erroneous detection due to diffused reflection of light in the smoke sensing chamber in the light emitting/receiving part of the optical element, and has a problem of being large. Furthermore, the labyrinth wall is insufficient to prevent the intrusion of ambient light, and the flow resistance increases, the influx of naturally flowing smoke decreases, and the smoke may reach the light receiving and emitting part of the optical element. Have difficulty. Conventional labyrinth walls also have the problem of being complicated in structure and large in size.
According to the present invention, it is possible to provide a smoke sensor that detects smoke in a short period of time.

BRIEF DESCRIPTION OF THE DRAWINGS It is the perspective view which looked at the smoke sensor 1 of one embodiment of this invention from the downward direction. 1 is a perspective view of the smoke sensor 1 as seen from above; FIG. 1 is a front view of the smoke sensor 1; FIG. 2 is a rear view of the smoke sensor 1; FIG. 2 is a left side view of the smoke sensor 1; FIG. 2 is a right side view of the smoke sensor 1; FIG. 2 is a plan view of the smoke sensor 1; FIG. 3 is a bottom view of the smoke sensor 1; FIG. 3 is a front view of the mounting member 2; FIG. 2 is a left side view of the mounting member 2; FIG. 4 is a perspective view of the housing base 4 as seen from below; FIG. 4 is a front view of a housing base 4; FIG. 4 is a left side view of the housing base 4; FIG. FIG. 4 is a cross-sectional view of the housing base body 4 viewed from the cutting plane line JJ in FIG. 3; 4 is a bottom view of the housing base 4; FIG. FIG. 9 is a cross-sectional view of the smoke sensor 1 seen from the cutting plane line BB in FIG. 8; FIG. 5 is a cross-sectional view of the smoke sensor 1 seen from the cutting plane line HH in FIG. 4; FIG. 4 is a cross-sectional view of the smoke sensor 1 seen from the cutting plane line FF in FIG. 3; FIG. 6 is a cross-sectional view of the smoke sensor 1 seen from the section line II of FIG. 5; 4 is an exploded perspective view showing an exhaust guide member 50, a light shielding cover 70 and the like related to the detection space forming body 40 upside down. FIG. FIG. 3 is a cross-sectional view of the smoke sensor 1 as seen from the left side for explaining the passage of smoke; FIG. 22(1) is a horizontal sectional view showing scattered light due to smoke in the detection area within the detection space forming body 40, and FIG. is a horizontal cross-sectional view for explaining the function of the light shielding member 118 forming the . 3 is a perspective view showing a partition member 30 and an introduction light shielding member 41; FIG. 4 is a perspective view of the partition member 30 as seen from below. FIG. 3 is a front view of a partition member 30; FIG. 3 is a left side view showing an introduction light shielding member 41, an extraction light shielding member 42, and an exhaust guide member 50. FIG. 4 is a perspective view of the introduction light shielding member 41 and the lead-out light shielding member 42 viewed from below near the rear surface; FIG. 4 is a perspective view of the lead-out light shielding member 42 and the exhaust guide member 50 viewed from below near the front. FIG. 4 is a front view of the introduction light shielding member 41. FIG. 4 is a rear view of the introduction light shielding member 41. FIG. 4 is a bottom view of the introduction light shielding member 41. FIG. 4 is a rear view of a lead-out light shielding member 42; FIG. 4 is a plan view of a lead-out light shielding member 42; FIG. 3 is a perspective view of a light shielding cover 70; FIG. 4 is a perspective view of the light shielding cover 70 as seen from below; FIG. 4 is a front view of a light shielding cover 70; FIG. 3 is a perspective view of a housing body 5; FIG. 3 is a perspective view of a display piece 91; FIG. FIG. 10 is a perspective view of the display piece 91 as seen from below; 5 is a cross-sectional view showing a state in which the display piece 91 is attached to the housing body 5 to form the indicator 90. FIG. 3 is a block diagram showing an electronic circuit device 60 of the smoke sensor 1; FIG. 4 is a flowchart for explaining the operation of a processing circuit 62 provided in an electronic circuit device 60 of the smoke sensor 1; 4 is a graph showing the time course of the output voltage from the light receiving element 113 corresponding to the concentration of smoke in the detection area 111. FIG. 4 is a waveform diagram for explaining the operation of a display element 92 of indicator 90. FIG.

FIG. 1 is a bottom perspective view of a smoke sensor 1 according to an embodiment of the present invention, FIG. 2 is a top perspective view of the smoke sensor 1, and FIG. 4 is a rear view of the smoke sensor 1, FIG. 5 is a left side view of the smoke sensor 1, FIG. 6 is a right side view of the smoke sensor 1, and FIG. 8 is a plan view of the smoke sensor 1, and FIG. 8 is a bottom view of the smoke sensor 1. FIG. With reference to these drawings, smoke sensor 1 basically has mounting member 2 and housing 3 . The overall shape of the housing 3 is in the shape of a flat square prism, and includes a housing base 4 fixed to the mounting member 2 and a housing main body 5 protruding outward from the housing base 4 with a step 7 formed thereon. have The mounting member 2 is attached by bolts 8 or the like to the ceiling 6 of the room of the building where smoke is to be detected.

A plurality of intake ports 11 are formed in each of the four peripheral walls 10 of the housing base 4 . A lower portion 21 of the housing main body 5 has a bulging portion 22 that extends elongatedly in the front and rear directions and bulges downward, and concave portions 23 that bulge upward on the left and right sides of the bulging portion 22 . The protrusion 22 and the recess 23 form an exhaust port 24 facing outward on the left and right sides. The smoke generated by the fire immediately rises and reaches the lower surface of the ceiling 6, moves horizontally along the ceiling 6, and flows between the lower surface of the ceiling 6 and the step 7 from the air inlet 11 to the centrifugal fan 100 ( 21), smoke is detected by the detection means 110 in the housing 3, and is forcibly discharged downward from the exhaust port 24. FIG. When smoke is detected by the detection means 110, the indicator 90 flashes or lights up continuously to emit light to indicate the occurrence of fire.

9 is a front view of the mounting member 2, and FIG. 10 is a left side view of the mounting member 2. FIG. A mounting plate 81 of the mounting member 2 has a pair of left and right projections 82 and a pair of left and right locking pieces 83 formed closer to the rear side than the projection 82 (to the left in FIG. 10) on the lower surface thereof. A through hole 84 (FIG. 2) formed in the mounting plate 81 corresponds to the locking piece 83 and facilitates injection molding of the mounting member 2 .

11 is a perspective view of the housing base 4 as seen from below, FIG. 12 is a front view of the housing base 4, FIG. 13 is a left side view of the housing base 4, and FIG. FIG. 15 is a cross-sectional view of the housing base 4 viewed from JJ, and FIG. 15 is a bottom view of the housing base 4. FIG. With reference to these drawings, the upper surface of the upper plate 12 of the housing base 4 is formed with a support piece (not shown) that is supported by being locked to the locking piece 83 of the mounting member 2 . On the upper plate 12, holding pieces 13 for elastically holding and positioning the projections 82 of the mounting member 2 are formed by through-holes around the holding pieces 13. As shown in FIG.

At the lower end of each peripheral wall 10, an annular outward flange 14 forming a step 7 is formed, and a locking pawl 15 extending downward is formed for detachably connecting to the housing body 5. As shown in FIG. A line lead-in port 16 is formed downwardly from the outward flange 14 . A housing recess 17 for housing and fixing the centrifugal fan 100 is formed at a substantially central position of the upper plate 12 . A filter holding projection 18 is formed on the upper plate 12 . A mounting portion 19 for mounting the filter 87 facing the intake port 11 of each peripheral wall 10 is formed.

16 is a sectional view of the smoke sensor 1 seen from the section line BB in FIG. 8, and FIG. 17 is a sectional view of the smoke sensor 1 seen from the section line HH in FIG. 18 is a cross-sectional view of the smoke sensor 1 seen from the section line FF in FIG. 3, and FIG. 19 is a cross-sectional view of the smoke sensor 1 seen from the section line II in FIG. FIG. 20 is an exploded perspective view showing the exhaust guide member 50 and the light shielding cover 70 related to the detection space forming body 40, upside down, and FIG. It is a sectional view seen from the left side. With reference to these drawings, partition members 30 are arranged below the housing base 4 with spacer projections 88 spaced apart from each other. The outward flange 14 of the housing base 4 abuts on the left and right outer edges of the partition pieces 34 and 35 of the partition member 30 . As a result, an air chamber 32 is formed between the lower surface of the upper plate 12 of the housing base 4 and the upper surface of the partition plate 31 of the partition member 30 . Air forcedly sucked by the centrifugal fan 100 from the inlet 11 through the filter 87 is collected in the air chamber 32 . In FIG. 17, air flow is indicated by solid arrows. The centrifugal fan 100 has an inlet 101 that opens downward facing the air chamber 32, and the air from the inlet 101 is discharged from an outlet 102 that opens toward the front. Air from the outlet 102 is supplied to the detection space forming body 40 in the detection means 110 . The detection space forming body 40 is composed of an introduction light shielding member 41 and a lead light shielding member 42 combined therewith. Between the outlet 102 of the centrifugal fan 100 and the introduction port 43 formed in the hanging wall 47 of the introduction light blocking member 41, an air shielding ridge 89 formed on the lower surface of the upper plate 12 of the housing base 4 and a hanging A guide space 49 is formed by a U-shaped air guide protrusion 48 extending from the wall 47 to the rear (left side in FIG. 21). The hanging wall 47 closes the air chamber 32 on both left and right sides of the outlet 102 of the centrifugal fan 100 .

A temperature detection element 127 that detects the temperature of the air is arranged, for example, in the air chamber 32 .

Air is supplied to the detection space 45 formed in the detection space forming body 40 from an introduction port 43 near the upper rear surface of the detection space 45 . The air in the detection space 45 is led out from an outlet port 44 formed in the lower plate 46 of the lead-out light shielding member 42 near the front of the lower part of the detection space 45 . The air from the outlet port 44 passes through a guide path 52 between the lower surface of the lower plate 46 of the outlet light shielding member 42 and the upper surface of the air guide plate 51 that slopes downward toward the rear side of the exhaust guide member 50, and then passes through the rear surface. direction (leftward in FIG. 21), through the exhaust guide port 53 of the exhaust guide member 50, the exhaust space between the lower surface of the cover plate piece 54 and the lower surface of the protruding portion 22 of the housing body 5 and its vicinity. 55, it is discharged downwardly and outwardly from the exhaust port 24. As shown in FIG.

FIG. 22(1) is a horizontal sectional view showing scattered light due to smoke in the detection area 111 within the detection space forming body 40, and FIG. 121 is a horizontal cross-sectional view for explaining the function of the light shielding member 118 forming 121. FIG. These FIGS. 22(1) and 22(2) correspond to FIG. 19 described above.

The detection means 110 has a detection space forming body 40, and the detection space forming body 40 forms a light-shielding detection space 45 in the middle of the passage through which air containing smoke is sucked and pumped by the centrifugal fan 100, Within this detection space 45 is a smoke detection area 111 . The detection space 45 is a rectangular shape formed by the partition plate 131 of the lead-in light shielding member 41 and the hanging wall 47, and by the left and right side walls 133 and 134 of the lead-out light shielding member 42, the front wall 135, and the lower plate 136. A body, for example, a cuboid space. The lead-in light shielding member 41 and the lead-out light shielding member 42 are made of light-shielding synthetic resin or the like, and at least the inner surface forming the detection space 45 may be black for suppressing irregular reflection.

The hanging wall 47 of the introduction light shielding member 41 is provided with a light emitting element holding portion 137 in which a recess for holding the light emitting element 112 from above is formed on the rear side. Light emitting element 112 emits light toward detection region 111 . A light-receiving element holding portion 138 having a recess for holding the light-receiving element 113 from above is also provided on the back side of the hanging wall 47 . The light receiving element 113 has an optical axis that intersects the optical axis of the light emitting element 112 in the detection area 111 .

The light-emitting path forming member 115 is light-shielding, hollow, connected to the light-emitting element holding portion 137 (FIG. 22) at the hanging wall 47, extends along the optical axis of the light-emitting element 112, and extends along the light-emitting element 112 with respect to the detection area 111. Near 112, a light emission path 114 indicated by a phantom line is formed along which light from the light emitting element 112 follows. The light-emitting path forming member 115 defines the spread along the light-emitting optical axis of the light emitted from the light-emitting element 112 necessary for detecting smoke in the detection area 111 according to the directional characteristics of the light-emitting element 112, that is, defines the light-emitting optical axis. A range in which a predetermined luminous intensity or illuminance can be obtained, such as a directivity angle and a half-value angle, is defined on the circumference within a virtual vertical plane centered on the center, and low-intensity light unnecessary for smoke detection is directed into the detection space. Limits radiation and suppresses diffuse reflection.

The light-receiving path forming member 117 is light-shielding, hollow, connected to the light-receiving element holding portion 138 (FIG. 22) at the hanging wall 47, extends along the optical axis of the light-receiving element 113, and extends along the optical axis of the light-receiving element 113 with respect to the detection area 111. A light-receiving path 116 indicated by a phantom line along which light to the light-receiving element 113 follows is formed near 113 . The light-receiving path forming member 117 regulates the spread of incident light along the light-receiving optical axis of the light-receiving element 113 necessary for smoke detection from the detection area 111 according to the directivity characteristics of the light-receiving element 113, and is unnecessary for smoke detection. , restricts the incidence of irregularly reflected light from areas other than the detection area 111 to prevent erroneous detection.

Components corresponding to the light-emitting element holding portion 137 and the light-receiving element holding portion 138 of the introduction light-shielding member 41 are also provided below the lead-out light-shielding member 42, and are indicated by the same reference numerals with the suffix a. , which are combined above and below to perform a holding function.

The light shielding member 118 functions to define a light shielding space 121 around the optical axis of the light receiving element 113 and corresponding to the directional characteristics. 133. The light-shielding space 121 extends along the optical axis of the light-receiving element 113 to the side opposite to the light-receiving element 113 with respect to the detection area 111 , opens to face the detection area 111 , and is located away from the detection area 111 . is closed by side wall 133 .

The light shielding member 118 is provided on the opposite side of the light receiving element 113 with respect to the detection area 111 along the optical axis of the light receiving element 113 and at a position facing the light receiving element 113. is a predetermined value or more, for example, the viewing angle is extended so as to cover and wrap.

As shown in FIG. 22(2), the light-shielding member 118 prevents the light emitted from the light-emitting element 112 in the detection space 45 from being diffusely reflected by the light-shielding member 118 as indicated by the arrows. Since the light does not reach the light receiving element 113 until after entering the light shielding space 121 of 118, the diffusely reflected light reaching the light receiving element 113 can be reduced. The light entering the light shielding space 121 of the light shielding member 118 has already been weakened by diffused reflection in the detection space 45, so that the light reaches the light receiving element 113 and enters the range indicated by the imaginary line 119. The reflected light of is naturally weakened, and therefore does not adversely affect the detection operation of the light receiving element 113 by the photocurrent. Since the light shielding member 118 can be realized by a simple structure such as partition walls such as the light shielding plates 122 and 123, the constituent elements including the detection space forming body 40 and the light shielding member 118 are made of synthetic resin, so that injection molding can be performed. molds can be simplified.

At the end of the light receiving path forming member 117 close to the detection area 111, at a position away from the light emitting element 112 with respect to the light receiving path 116 of the light receiving element 113, outside the light emitting path 114 of the light emitting element 112, and vertically in the detection space 45. A light-blocking protrusion 125 is provided that extends and protrudes. This protrusion 125 is positioned outside the light emission path 114 of the light emitting element 112 and thus within the detection space 45 without impeding the illumination of the light emitted from the light emitting element 112 onto the detection area 111 with the extent necessary for smoke detection. It is certain to prevent the light irregularly reflected by the light receiving element 113 from entering the light receiving element 113 .

In another embodiment, the light emitting element 112 extends along the optical axis of the light emitting element 112 on the side opposite to the detection area 111, opens toward the detection area 111, and closes at a position away from the detection area 111, It is possible to further provide another light shielding member that defines the light shielding space 121 as a range corresponding to the directivity around the optical axis of the light emitting element 112 . As a result, irregular reflection of light from the light emitting element 112 in the detection space 45 can be further prevented.

23 is a perspective view showing a partition member and an introduction light shielding member, FIG. 24 is a perspective view of the partition member as seen from below, and FIG. 25 is a front view of the partition member. With reference to these drawings, the end face on the back side of the U-shaped air guide protrusion 48 is a U-shape in a plan view that stands downward near the outlet 102 of the centrifugal fan 100 on the partition plate 31 of the partition member 30 . It fits into the letter-shaped shielding protrusion 33 and comes into contact with the front side surface of the shielding protrusion 33 to guide air to the inlet 43 . In the partition member 30 , partition pieces 34 and 35 extending from the side portion of the partition plate 31 to the front side block the air chamber 32 between the upper plate 12 of the housing base 4 and the both sides of the introduction light shield member 41 . A guide piece 36 hangs down from the partition plate 31 so as to face the hanging wall 47 of the introduction light shielding member 41 , and a shielding wall 37 is formed near the light emitting element 112 .

26 is a left side view showing the introduction light-shielding member 41, the lead-out light-shielding member 42, and the exhaust guide member 50, and FIG. 27 is a perspective view of the introduction light-shielding member 41 and the lead-out light-shielding member 42 seen from below near the back. FIG. 28 is a perspective view of the lead-out light shielding member 42 and the exhaust guide member 50 viewed from below near the front. 29 is a front view of the introduction light-shielding member 41, FIG. 30 is a rear view of the introduction light-shielding member 41, and FIG. 32 is a rear view of the lead-out light shielding member 42, and FIG. 33 is a plan view of the lead-out light shielding member 42. FIG.

With reference to these drawings, the lead-out light shielding member 42 is formed with a partition plate 139 that protrudes and extends to the front side from approximately the middle position of the front wall 135 . The upper surface of the partition plate 139 forms a guide space between the upper surface of the partition plate 139 and the lower surface of the upper plate 12 of the housing base body 4 together with the partition pieces 34 and 35 of the partition member 30, so that the filter 87 in the peripheral wall 10 can be guided from the intake port 11 on the front side. Air is directed through the air chamber 32 and overlaps the lower surface of the outward flange 14 on the front face of the housing base 4 . Engagement portions 141 and 142 are formed at the rear end portions of the left and right side walls 133 and 134 of the lead-out light shielding member 42 to extend inward and up and down. The leading light shielding member 41 and the leading light shielding member 42 are assembled by engaging the ends. The left and right locking claws 151 and 152 of the lead-out light shielding member 42 are detachably locked to the locking recesses 56 and 57 of the exhaust guide member 50 .

34 is a perspective view of the light shielding cover 70, FIG. 35 is a perspective view of the light shielding cover 70 viewed from below, and FIG. The light shielding cover 70 covers the electronic circuit device 60 mounted on the lower surface of the partition plate 31 of the partition member 30 from below.

Referring again to FIG. 19 , connector 61 is arranged on substrate 63 of electronic circuit device 60 so as to face connector wall 38 of partition member 30 . and flexible lead wires are connected to each other, and a display element 92 realized by a light emitting diode or the like for the indicator 90 is erected downward facing the display piece 91 and connected to each of these components. A processing circuit 62 and the like realized by a microcomputer or the like are provided to control their operations. Temperature detection element 127 is provided in air chamber 32 described above, for example, with its lead wire inserted through connection hole 39 formed in partition member 30 . The substrate 63 is fixed by screwing bolts 64 and 65 into screw holes 86 (FIG. 24) of the partition member 30 and screw holes 88 (FIG. 15) of the housing base 4 .

The light shielding cover 70 has a lower plate 71 , left and right side plates 72 and 73 , a rear plate 75 having a notch 74 for the connector 61 , a shielding wall 76 , and left and right front partition walls 77 and 78 . The shielding wall 76 and the shielding wall 37 of the partition member 30 are arranged side by side when the assembly is completed. A through hole 79 is formed in the lower plate 71 through which the display element 92 is exposed downward.

37 is a perspective view of the housing body 5. FIG. A display piece 91 for an indicator 90 is fixed near the back of the bulging portion 22 in the lower portion 21 of the housing body 5 . On the inner surfaces of the left and right side walls 25 , 26 of the housing body 5 , locking protrusions 27 are formed for detachably locking the locking claws 15 of the housing base 5 . A notch 29 for the line inlet 16 is formed in the rear wall 28 of the housing body 5 .

38 is a perspective view of the display piece 91, FIG. 39 is a perspective view of the display piece 91 viewed from below, and FIG. Referring to these drawings, the display piece 91 has an annular protrusion 94 on the upper surface of a disc-shaped base 93, and elongated and flat display protrusions on the lower surface of the base 93 in the front and back directions. Article 95. The lower portion of the display ridge 95 is formed in an arcuate shape that protrudes downward in both the cross section in the front-rear direction and the cross section in the left-right direction. The display element 92 faces the concave portion of the annular protrusion 94 through the through hole 79 of the light shielding cover 70, and light from the display element 92 is irradiated. Since the synthetic resin materials of the housing body 5 and the display piece 91 have different refractive indices, the light from the display element 92 propagates only to the display ridges 95 of the display piece 91 and shines when viewed from below. Since it is obtained, the aesthetic feeling is improved.

FIG. 41 is a block diagram showing the configuration of the electronic circuit device 60 of the smoke sensor 1. As shown in FIG. Power from the power supply terminal 66 of the connector 61 is supplied to the fan 100 from the fan power supply circuit 144 . The rotational speed of fan 100 is detected by rotational speed detector 145 and provided to processing circuitry 62 . The processing circuit 62 drives the light emitting element 112 by means of the light emission drive circuit 146 . The output of the light receiving element 113 is applied to the processing circuit 62 via the amplifier circuit 147 . A communication terminal 67 of the connector 61 is connected to the processing circuit 62 via the communication circuit 148, thereby enabling the processing circuit 62 to send and receive signals with a remote display device or the like. The processing circuit 62 controls lighting of the display element 92 . A control power supply circuit 149 is provided. The detection means 110 is composed of a detection space forming body 40, an electronic circuit device 60 including detection circuits such as a light emitting element 112, a light receiving element 113, and a processing circuit 62, and the like.

FIG. 42 is a flow chart for explaining the operation of the processing circuit 62 provided in the electronic circuit device 60 of the smoke sensor 1. FIG. Step s1 transfers to step s2 to initialize processing circuitry 62 and perform processing operations for indicator 90, including display element 92, in step s3. At step s4, a processing operation for transmitting fire information is performed. In step s5, it is determined whether or not the time W measured by the smoke detection timer provided in the processing circuit 62 has passed a predetermined set time W0 (for example, 0.5 seconds) or more.If not, the process returns to step s3. When it is determined in step s5 that the clocked time W has passed 0.5 seconds or more, which is the predetermined set time W0, the light emitting element 112 is turned on in step s6. At step s7, the light receiving signal from the light receiving element 113 is taken into the processing circuit 62, and at step s8, the light emitting element 112 is extinguished. In step s9, the concentration of smoke is calculated from the output voltage level of the light receiving signal from the light receiving element 113, and the occurrence of fire is determined. When the output voltage of the light receiving signal from the light receiving element 113 is equal to or higher than a predetermined threshold value corresponding to the concentration of detected smoke and it is determined that a fire has occurred, the display element 92 is turned on in a predetermined manner. , to provide a visual indication of the occurrence of a fire, such as by flashing or lighting continuously. If there is no fire, the display element 92 remains extinguished. At step s10, the time W of the smoke detection timer is cleared to zero, and the process returns to step s3. In this way, the density of smoke is detected every predetermined set time W0.

FIG. 43 is a graph showing the time course of the output voltage from the light receiving element 113 corresponding to the concentration of smoke in the detection area 111. In FIG. The output voltage of the light receiving element 113 corresponds to the concentration of smoke contained in the air passing through the detection area 111 in the detection space 45 of the detection space forming body 40 . In step s9 of FIG. 42, the processing circuit 62 responds to the output of the light receiving element 113, and determines that a fire has occurred when the output voltage of the light receiving element 113 is, for example, equal to or greater than a predetermined threshold indicated by reference character L1. Then, the display element 92 is caused to display the occurrence of fire.

FIG. 44 is a waveform diagram explaining the operation of the display element 92 of the indicator 90. FIG. If the concentration of smoke contained in the air passing through the detection area 111 is low, and therefore the output of the light receiving element 113 is less than the threshold value L1 in FIG. 43, the display element Reference numeral 92 indicates that the processing circuit 62 blinks the lighting time W1 and the lighting time W2 of FIG. 44 at regular intervals.

If the density of smoke is high and therefore the output of the light receiving element 113 is equal to or greater than the threshold value L1 in FIG. flashing operation. At time t1, when the output of the light-receiving element 113 becomes equal to or higher than the threshold value L1, the display element 92 is turned on for the time W1 and then turned off for the next time W2. Such operations are repeated.

The processing circuitry 62 is also responsive to the output of the temperature sensing element 127 to indicate that the display element of the indicator 90 is activated when the sensed air temperature is equal to or greater than a predetermined value in the event of a fire, regardless of smoke density. 92 is driven for display.

In another embodiment, the processing circuit 62 may perform continuous lighting instead of the blinking operation of FIG. 44, and may perform acoustic indication or vibration indication instead of these visual indications. .

The present invention enables the following embodiments.
(1) (a) the housing 3,
an intake port 11 opening outward at the upper portion of the housing 3;
an exhaust port 24 opening at the bottom of the housing 3;
a housing 3 having a passage for guiding air from the intake port 11 to the exhaust port 24;
(b) a suction means 100 for sucking air from the intake port 11 and exhausting it to the exhaust port 24 through the passage;
(c) a smoke detector characterized by including detection means 110 provided in the middle of the passage for detecting smoke in the air;

A smoke detector is provided that quickly detects smoke. For example, smoke generated by a fire immediately rises to reach the lower surface of the ceiling 6, travels along the ceiling 6, and exists around the smoke sensor 1 at and near the lower surface of the ceiling 6. Smoke in the early stages of fire is forced into the passage from an intake port 11 that opens outward at the upper portion of the housing 3 by a suction means 100, for example, a centrifugal fan, and is guided to detection means for detecting smoke in the air. Then, it is forced to exhaust through the passageway to the exhaust port 24 and does not stay in the passageway. Therefore, the smoke moving along the ceiling 6 smoothly flows into the detection means 110, and the smoke can be detected quickly and reliably. Instead of the centrifugal fan, another configuration for sucking and pumping air, or an axial fan or the like may be used.

The intake port 11 also includes a configuration in which it faces the lower surface of the ceiling 6 at an upper portion of the housing 3 with a gap downward from the lower surface of the ceiling 6 and opens directly upward or obliquely upward. The exhaust port 24 in the lower part of the housing 3 includes a structure that opens directly below the housing 3, obliquely downward, or outward, and is arranged below the intake port 11. As shown in FIG.

(2) At least one of the passage from the intake port 11 to the inlet 43 of the detection space forming body 40 and the passage from the outlet 44 of the detection space forming body 40 to the exhaust port 24,
It is characterized by being light-shielding and bent in at least three axial directions along the direction of air flow.

A smoke sensor 1 is provided that reliably prevents ambient light from entering the detection space 45 that optically detects light scattered by smoke. Intrusion of ambient light into the detection space 45 can be prevented with a simple structure. Since ambient light from the outside of the installation space, for example, a room in the building, does not enter the detection space 45, there is no danger of erroneously detecting the presence of smoke.

The passage leading from the intake port 11 to the detection space 45 bends once or more in each of the directions of the three orthogonal XYZ axes, that is, changes the direction of smoke flow twice or more. For example, in the embodiment described later, air from the left and right air intakes 11 moves in the horizontal X-axis direction (that is, in the left-right direction) within the air chamber 32 and then is drawn into the inlet 101 of the centrifugal fan 100. and moves downward in the Z-axis direction, thereby changing the direction of the flow once, and then sucked by the centrifugal fan 100 and moving downward in the Z-axis direction to the front side from the outlet 102 of the centrifugal fan 100 The air is introduced into the detection space 45 after moving in the Y-axis direction toward and the flow direction changes once more, so that the air reaches the introduction port 43 of the detection space 45 from the left and right intake ports 11 By then, it is bent in at least three axial directions.

In the smoke sensor 1 incorporating the suction means 100, even if ambient light from the outside enters the inlet end of the intake port 11, it can be Ambient light entering from the entrance end does not reach the detection space 45 . Also, by not providing a light-shielding wall having a complicated structure such as the conventional labyrinth wall, the structure of the passage is simplified, design and manufacturing are facilitated, and cost reduction can be expected.

In another embodiment, in the smoke sensor 1 incorporating the suction means 100, a , a filter 87 having a porous structure may be attached. This makes it difficult for foreign substances such as dust and insects, or disturbance light from the outside to enter the detection space 45 other than smoke. According to the present invention, the structure of the passage is simplified, making it easier for dust and insects to enter. The filter 87 may be made of a porous material such as sintered metal, synthetic resin, non-woven fabric, or paper having three-dimensional and complicatedly curved communicating pores, and may be elastic or rigid. There may be.

(3) The detection space forming body 40 is
an inlet 43 through which air from the passage is introduced into the detection space 45;
an outlet 44 through which air from the detection space is led to the passage,
A detection region 111 is arranged in the middle of the air path from the inlet 43 to the outlet 44 .

In the detection space 45, there are a smoke detection region 111, a light shielding member 118 for preventing irregular reflection, a projection 125, and the like.

Since the detection area 111 is arranged in the middle of the air path from the inlet 43 to the outlet 44, the air is always flowing and does not stay, so smoke can be quickly detected.

(4) The detection means 110
a detection space forming body 40 which forms a light-shielding detection space 45 in the middle of the passage and has a smoke detection region 111 in the detection space 45;
a light-emitting element 112 that emits light toward the detection region 111;
a light receiving element 113 having an optical axis that intersects the optical axis of the light emitting element 112 in the detection area 111;
It extends along the optical axis of the light receiving element 113 to the side opposite to the light receiving element 113 with respect to the detection area 111, opens facing the detection area 111, closes at a position away from the detection area 111, and extends along the optical axis of the light receiving element 113. A light shielding member 118 that defines a light shielding space in a range corresponding to the directional characteristics in the periphery (the light shielding member 118 may be composed of a pair of light shielding plates 122 and 123, a partition plate 131, a lower plate 136, and a side wall 133). good.),
and a detection circuit 60 responsive to the output of the light receiving element 113 and detecting that the output corresponds to smoke.

To provide a smoke sensor 1 which has a simple structure for preventing irregular reflection of light in a detection space 45 for optically detecting scattered light due to smoke, is miniaturized, and is inexpensive.

The light receiving element 113, for example, a silicon photodiode, has a viewing angle or a directivity half-value angle, and the sensitivity outside the viewing angle is low with respect to the front within the viewing angle. In the present invention, the spread of the light incident on the light receiving element 113 is arranged on the opposite side of the light receiving element 113 with respect to the detection area 111 along the optical axis of the light receiving element 113 and at the position facing the light receiving element 113. 22(1), a light shielding member 118 extending to cover and envelop the viewing angle is provided. The light shielding member 118 is open facing the detection area 111 and closed at a position away from the detection area 111 .

Due to this light shielding member 118, the light emitted from the light emitting element 112, for example, a light emitting diode, is diffusely reflected in the detection space 45, but it is not after the diffusely reflected light enters the light shielding space 121 of the light shielding member 118. 22(2), the diffusely reflected light reaching the light receiving element 113 can be reduced. The light entering the light shielding space 121 of the light shielding member 118 has already been weakened in energy, which is the amount of light, due to diffused reflection in the detection space 45. Therefore, the reflected light reaching and incident on the light receiving element 113 is naturally weakened. Therefore, the detection operation of the light receiving element 113 by the photocurrent is not adversely affected. Since the light shielding member 118 can be realized by a simple structure such as a partition, if the structural elements including the detection space forming body 40 and the light shielding member 118 are made of synthetic resin, the mold for injection molding can be simplified.

(5) a light-shielding light-emitting path forming member 115 that extends along the optical axis of the light-emitting element 112 and forms a light-emitting path 114 for light from the light-emitting element 112 near the light-emitting element 112 with respect to the detection area 111;
and a light-shielding light-receiving path forming member 117 extending along the optical axis of the light-receiving element 113 and nearer to the light-receiving element 113 with respect to the detection area 111 and forming a light-receiving path 116 of light to the light-receiving element 113 . .

The light-emitting path forming member 115 defines the spread of the light emitted from the light-emitting element 112 necessary for detecting smoke in the detection area 111 along the light emission optical axis according to the directivity of the light-emitting element 112. As shown in the light-emitting path 114, A range in which a predetermined luminous intensity or illuminance can be obtained, such as a directivity angle and a half-value angle, is defined on the circumference within a virtual vertical plane centered on the light emission optical axis, and low-intensity light unnecessary for smoke detection is defined. Limits radiation to the detection space and suppresses diffuse reflection.

The light-receiving path forming member 117 defines the spread of incident light along the light-receiving optical axis of the light-receiving element 113 necessary for smoke detection from the detection area 111 according to the directional characteristics of the light-receiving element. It restricts the incidence of irregularly reflected light from outside the detection area 111 to prevent erroneous detection.

In another embodiment, the light emitting element 112 extends along the optical axis of the light emitting element 112 on the side opposite to the detection area 111, opens toward the detection area 111, and closes at a position away from the detection area 111, It is possible to further provide another light shielding member that makes a range corresponding to the directivity characteristic around the optical axis of the light emitting element 112 a light shielding space. As a result, irregular reflection of light from the light emitting element 112 in the detection space 45 can be further prevented.

(6) detection at the end of the light receiving path 116 of the light receiving element 113 near the detection region 111, at a position away from the light emitting element 112 with respect to the light receiving path 116 of the light receiving element 113, and outside the light emitting path 114 of the light emitting element 112; A feature is that a light-shielding projection 125 protruding into the space 45 is provided.

The projection 125 is positioned outside the light emission path 114 of the light emitting element 112 and thus within the detection space 45 without impeding the illumination of the detection area 111 of the light emitted from the light emitting element 112 with the spread required for smoke detection. It is certain to prevent the irregularly reflected light from entering the light receiving element 113 .

(7) A temperature detection element 127 for detecting the temperature of the air is provided in the middle of the passage,
The detection means is characterized in that it not only detects smoke, but is responsive to the temperature output of temperature sensing element 127 to detect that the temperature output corresponds to fire.

By detecting both the smoke and the temperature of the air that may contain the smoke, the occurrence of a fire or the like can be quickly detected. The temperature detection element 127 , for example, a thermistor, may be arranged upstream of the suction means 100 , that is, closer to the air inlet 11 than the suction means 100 .

(8) A smoke sensor that prevents diffused reflection without requiring forced suction,
a detection space forming body 40 which forms a light-shielding detection space 45 in the middle of an air passage and has a smoke detection region 111 in the detection space 45;
a light-emitting element 112 that emits light toward the detection region 111;
a light receiving element 113 having an optical axis that intersects the optical axis of the light emitting element 112 in the detection area 111;
It extends along the optical axis of the light receiving element 113 to the side opposite to the light receiving element 112 with respect to the detection area 111, opens facing the detection area 111, closes at a position away from the detection area 111, and extends along the optical axis of the light receiving element 113. a light shielding member 118 having a light shielding space 121 corresponding to the directional characteristics in the periphery;
and a detection circuit 60 responsive to the output of the light receiving element 113 and detecting that the output corresponds to smoke.

As described above, the smoke sensor 1 is provided with a simple and compact structure for preventing diffuse reflection of light in the detection space 45 for optically detecting scattered light due to smoke.

The light receiving element 113 has a viewing angle or a directivity half-value angle, and the sensitivity outside the viewing angle is low with respect to the front within the viewing angle. In the present invention, the spread of the light incident on the light receiving element 113 is arranged on the opposite side of the light receiving element 113 with respect to the detection area 111 along the optical axis of the light receiving element 113 and at the position facing the light receiving element 113. 22(1), a light shielding member 118 extending to cover and envelop the viewing angle is provided. The light shielding member 118 is open facing the detection area 111 and closed at a position away from the detection area 111 .

Due to this light shielding member 118, the light emitted from the light emitting element 112, for example, a light emitting diode, is diffusely reflected in the detection space 45, but it is not after the diffusely reflected light enters the light shielding space 121 of the light shielding member 118. 22(2), which will be described later, it is possible to reduce diffusely reflected light reaching the light receiving element 113. As shown in FIG. The light entering the light shielding space 121 of the light shielding member 118 has already been weakened in energy, which is the amount of light, due to diffused reflection in the detection space 45. Therefore, the reflected light reaching and incident on the light receiving element 113 is naturally weakened. Therefore, the detection operation of the light receiving element 113 by the photocurrent is not adversely affected. Since the light shielding member 118 can be realized by a simple structure such as a partition, if the structural elements including the detection space forming body 40 and the light shielding member 118 are made of synthetic resin, the mold for injection molding can be simplified.

(9) (a) a housing having an air inlet, an air outlet, and a passage for guiding air from the air inlet to the air outlet;
(b) suction means for sucking air from the intake port, passing through the passage, and forcibly exhausting the air to the exhaust port;
(c) detection means provided in the middle of the passage for detecting smoke in the air;
(d) at least one of the passage from the inlet to the inlet of the detection space forming body and the passage from the outlet to the exhaust port of the detection space forming body,
The smoke sensor is characterized by being light-shielding and bent in at least three axial directions along the direction of air flow.

According to the present invention, a smoke detector is provided that detects smoke in a short period of time. Smoke in the initial stage of fire is sucked into the passage from the air inlet 11 of the housing 3 by a suction means 100, for example, a centrifugal fan, is guided to the detection means for detecting smoke in the air, passes through the passage, and exits the exhaust port. 24 is forced to exhaust and does not stay in the passage. Therefore, the smoke can smoothly flow into the detection means 110, and the smoke can be detected quickly and reliably. Instead of the centrifugal fan, another configuration for sucking and pumping air, or an axial fan or the like may be used.

In particular, at least one of the passage from the intake port 11 to the inlet 43 of the detection space forming body 40 and the passage from the outlet 44 of the detection space forming body 40 to the exhaust port 24 is light-shielding and allows air to pass through. Since it is bent in at least three axial directions along the direction of flow, the smoke sensor 1 reliably prevents disturbance light from entering the detection space 45 for optically detecting light scattered by smoke. . Intrusion of ambient light into the detection space 45 can be prevented with a simple structure. Since ambient light from the outside of the installation space, for example, a room in the building, does not enter the detection space 45, there is no danger of erroneously detecting the presence of smoke.

The passage leading from the intake port 11 to the detection space 45 bends once or more in each of the directions of the three orthogonal XYZ axes, that is, changes the direction of smoke flow twice or more. As an example, the configuration for bending air in at least three axial directions using the centrifugal fan 100 is as described above.

In the smoke sensor 1 incorporating the suction means 100, even if ambient light from the outside enters the inlet end of the intake port 11, it can be Ambient light entering from the entrance end does not reach the detection space 45 . Also, by not providing a light-shielding wall having a complicated structure such as the conventional labyrinth wall, the structure of the passage is simplified, design and manufacturing are facilitated, and cost reduction can be expected.

(10) (a) the housing 3,
an intake port 11 opening outward at the upper portion of the housing 3;
an exhaust port 24 opening at the bottom of the housing 3;
a housing 3 having a passage for guiding air from the intake port 11 to the exhaust port 24;
(b) a suction means 100 for sucking air from the intake port 11 and forcibly exhausting it to the exhaust port 24 through the passage;
(c) The heat sensor 1 is characterized by including a detecting means 127 which is provided in the middle of the passage and detects the temperature of the air.

A heat sensor is provided that quickly detects the temperature of the air. For example, the air generated by the fire, which may contain smoke, immediately rises to reach the lower surface of the ceiling 6, travels along the ceiling 6, and near the lower surface of the ceiling 6, and around the heat sensor. Smoke present in the early stage of fire is forced into the passage from the intake port 11 opened outward at the upper part of the housing by the suction means 100 and is led to the detection means 127 for detecting the temperature of the air, It is forcibly exhausted to the exhaust port 24 through the passage and does not stay in the passage. Therefore, the air moving along the ceiling 6 can smoothly flow into the detecting means 127, and the temperature of the air can be detected quickly and reliably. Temperatures of air generated by sources other than fire are also detected.

The intake port 11 also includes a configuration in which it faces the lower surface of the ceiling 6 at an upper portion of the housing 3 with a gap downward from the lower surface of the ceiling 6 and opens directly upward or obliquely upward. The exhaust port 24 in the lower part of the housing 3 is arranged below the intake port 11 , including configurations that open directly below the housing 3 , obliquely downward, or outward.

(11) A detection space forming body 40 which forms a light-shielding detection space 45 in the middle of a passage to which a fluid containing fine particles is supplied, and which has a fine particle detection region 111 in the detection space 45;
a light-emitting element 112 that emits light toward the detection region 111;
a light receiving element 113 having an optical axis that intersects the optical axis of the light emitting element 112 in the detection area 111;
It extends along the optical axis of the light receiving element 113 to the side opposite to the light receiving element 113 with respect to the detection area 111, opens facing the detection area 111, closes at a position away from the detection area 111, and extends along the optical axis of the light receiving element 113. a light shielding member 118 having a light shielding space 121 corresponding to the directional characteristics in the periphery;
and a detection circuit 60 that responds to the output of the light receiving element 113 and detects that the output corresponds to a particle.

When detecting fine particles contained in gas such as air or fluid such as liquid, for example, smoke in the air, diffused reflection of light in the detection space 45 for optically detecting light scattered by fine particles is prevented as described above. A device for detecting particulates in a fluid is provided that has a simple structure and a compact size for detection.
(12) A blower 100 provided in the housing 3 sucks ambient air from the intake port 11, supplies it to the detection area in the detection means for optically detecting smoke in the air, and emits smoke from the exhaust port 24. in the sensor,
At least one of the passage from the intake port to the detection region and the passage from the detection region to the exhaust port is
The smoke sensor is characterized by being bent in at least three axial directions along the direction of air flow.
(13) A filter 87 having a porous structure is provided in at least one of the passage from the intake port to the detection region and the passage from the detection region to the exhaust port.
In a smoke detector with a built-in blower, the flow path connecting from the intake port to the detection area is bent once or more in each of the three axial directions without providing a light shielding wall, and a light shielding wall is provided. However, since the path is curved once or more in all three axial directions, the ambient light that has entered the path does not reach the detection area.
This structure simplifies the structure of the flow path, making it easier for dust and insects to enter. By attaching a filter having a porous structure to either or both of them, it becomes difficult for anything other than smoke to enter the detection means.
(14) A blower provided in the housing draws in ambient air from above or from the upper side surface, and discharges the sucked air from the lower side or from the lower side surface;
The fire sensor is characterized by comprising detection means for detecting a fire from the sucked air.
(15) The detection means for detecting fire outputs a fire information signal or a fire signal corresponding to a physical phenomenon that serves as a reference for judging a fire, based on the sucked air.
It is possible to provide a sensor that has good smoke inflow and can detect smoke quickly and reliably. In other words, depending on the fire detection method, a fire information signal (a data signal containing numbers such as smoke concentration and temperature) or a fire signal (whether a fire has signal) is generated.
As means for detecting fire, a configuration may be adopted in which a plurality of fire detection means are mounted.

The present invention can be practiced not only in connection with smoke detectors, but can also be practiced in connection with heat sensors, and can be used not only for smoke in the air, but also for particulates contained in gases or liquids. can be implemented in a wide range of technical fields, such as for detecting

REFERENCE SIGNS LIST 1 smoke sensor 3 housing 4 housing base 5 housing main body 6 ceiling 11 intake port 18 filter holding projection 22 swelling portion 24 exhaust port 30 partition member 32 air chamber 40 detection space forming body 41 introduction light shielding member 42 lead light shielding member 43 inlet port 44 lead-out port 45 detection space 60 electronic circuit device 70 light-shielding cover 87 filter 90 indicator 91 display piece 92 display element 100 centrifugal fan 110 detection means 111 detection area 112 light-emitting element 113 light-receiving element 114 light-emitting path 116 light-receiving path 118 light-shielding member 121 light-shielding space 127 temperature detection element 137, 137a light emitting element holding portion 138, 138a light receiving element holding portion

Claims (2)

A blower provided in the housing draws in ambient air from an upper or upper side air intake port, passes through an air passage, and discharges the sucked air from a lower or lower side air outlet port,
A fire detection means for detecting a fire by the sucked air,
Forming a light-blocking smoke detection space in the middle of an air passage downstream of the blower , providing a smoke detection area in the smoke detection space,
at least one of the passage from the intake port to the smoke detection region and the passage from the smoke detection region to the exhaust port is formed by bending in at least three axial directions along the direction of air flow;
a light emitting element that emits light towards the smoke detection area;
a light receiving element having an optical axis that intersects the optical axis of the light emitting element in the smoke detection area;
extending along the optical axis of the light receiving element on the side opposite to the light receiving element with respect to the smoke detection area, open facing the smoke detection area, closed at a position away from the smoke detection area, and oriented around the optical axis of the light receiving element and a light shielding member having a light shielding space corresponding to the characteristics,
The fire detection means is
a processing circuit;
a temperature detection element provided in the air passage upstream of the blower;
a display element that performs a display operation representing the occurrence of a fire,
The processing circuit is
The light-emitting element is turned on every predetermined set time W0 to capture the light receiving signal from the light-receiving element, and then the light-emitting element is turned off,
driving the display element in response to the light receiving signal from the light receiving element when the concentration of smoke in the air is equal to or higher than a predetermined value L1;
A fire and smoke sensor that drives a display element regardless of the concentration of smoke when the temperature of the air detected by the temperature detection element reaches or exceeds a predetermined temperature at the time of fire occurrence . 2. The fire and smoke detector of claim 1, wherein said fire detection means comprises a plurality of fire detection means.

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