JP2019211800A - Smoke sensor - Google Patents

Abstract

To provide a smoke sensor for achieving excellent flow-in characteristics while preventing invasion of disturbance light to detection means for optically detecting smoke with a simple structure.SOLUTION: A blower 100 arranged inside a housing sucks circumferential air from a suction port 11, supplies the air to a detection area inside the detection means 110 for optically detecting smoke in the air, and discharges the air from an exhaust port 24. At least one of a passage from the suction port 11 to a detection area and a passage from the detection area to the exhaust port 24 is formed by bending at least in three axis directions along an air flowing direction.SELECTED DRAWING: Figure 21

Description

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

  In the present specification, the vertical direction is a space to be detected by the smoke detector. For example, in a building room, the vertical direction indicates a direction in a mounted state attached to the ceiling, and the vertical direction in a specific drawing. States that. Each component of the smoke detector is shown in the same direction as the front, back, left and right side, plane, and bottom of the smoke detector when mounted on the ceiling.

  Conventionally, in a photoelectric sensor, smoke is detected by detecting light scattered by smoke among light emitted from a light emitting element with a light receiving element. In this configuration, when disturbance light (that is, light from the installation space) enters the detection space, there is a problem that it is erroneously detected that smoke is present.

  A labyrinth wall (light-shielding wall) with good smoke inflow property was installed while preventing the intrusion of ambient light (Patent Document 1). However, the structure is complicated in order to achieve good inflow characteristics while preventing the intrusion of ambient light.

JP2007-13212

  An object of the present invention is to provide a smoke detector that achieves good inflow characteristics while preventing the intrusion of ambient light.

The present invention
In the smoke detector that sucks ambient air from the intake port by a blower provided in the housing, supplies it to the detection area in the detection means for optically detecting smoke in the air, and discharges it from the exhaust port.
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 detector is formed by bending in at least three axial directions along the air flow direction.

The present invention also provides:
A filter having a porous structure is provided in at least one of a passage from the intake port to the detection region and a passage from the detection region to the exhaust port.

  According to the present invention, in the smoke detector incorporating the blower, the flow path leading from the air inlet to the detection region is bent at least once in all three axial directions without providing a light shielding wall. Yes, because no light shielding wall is provided, disturbance light can easily enter the flow path, but the passage is bent once or more in all three axial directions, so disturbance light that has entered the passage reaches the detection area. do not do.

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

  This structure simplifies the structure of the flow path, making it easier for dust and insects to enter. However, in a smoke detector with a built-in blower, either between the intake port and the detection unit or between the detection unit and the exhaust port. In addition, by attaching a filter having a porous structure to both, it becomes difficult for non-smoke to enter the detection means.

The present invention
By a blower provided in the housing, the surrounding air is sucked in from the upper side or the upper side surface, and the sucked air is discharged from the lower side or the lower side surface.
A fire sensor comprising a detecting means for detecting a fire by the sucked air.

The present invention
The detection means for detecting a fire outputs a fire information signal or a fire signal corresponding to a physical phenomenon serving as a reference for judging a fire by the sucked air.

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

According to the present invention, 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, the fire information signal (signal of data including numbers such as smoke concentration and temperature) or the fire signal (whether a fire has occurred or not) Is generated).
As a means for detecting a fire, a configuration in which a plurality of fire detection means is mounted may be adopted.

  Smoke and heat generated by a fire have a characteristic of rising from the generation position and move along the ceiling after rising to the ceiling position. In the conventional technology, since the air intake is below the center of the sensor, smoke or heat reaches the air intake at a lower position away from the ceiling, and then smoke or heat flows into the detection unit. In order to detect it, it takes time to detect even after the smoke has arrived around the sensor, and in order to detect a fire quickly, the inflow of smoke or heat while maintaining the detection performance Need to be better.

  In the present invention, in a sensor incorporating a blower, a fire can be detected quickly and reliably by providing an intake port above or above the sensor and an exhaust port below or below the sensor. Is possible. For example, by providing the air inlet near the ceiling, smoke moving along the ceiling can be promptly and reliably guided to the detection area.

The present invention
A light-shielding detection space is formed in the middle of the air passage, and a smoke detection area is provided in this detection space.
A light emitting element for generating light toward the detection region;
A light receiving element having an optical axis that intersects the optical axis of the light emitting element in the detection region;
Along the optical axis of the light receiving element, the detection area extends to the opposite side of the light receiving element, opens toward the detection area, is closed at a position away from the detection area, and supports directional characteristics around the optical axis of the light receiving element. The smoke detector includes a light shielding member having a light shielding space in the range.

  In the conventional smoke detector, the upper part of the body that extends vertically is fixed to the ceiling, and the smoke naturally flows in from the lower part of the body, and the horizontal section provided to suppress the entry of ambient light The partition walls are arranged in a circle in a horizontal plane, pass through labyrinth walls configured in an annular shape, rise in the body and reach the optical element light emitting / receiving section, and the smoke remains there. Therefore, after the smoke is generated, the smoke reaches the optical element light emitting and receiving unit according to its natural convection, and therefore, it takes a relatively long time to detect the smoke. Also, the labyrinth wall lengthens the path of smoke movement, which also takes a relatively long time to detect smoke.

In this conventional smoke detector, there is a problem that the structure for preventing erroneous detection due to diffused reflection of light in the smoke sensing chamber in the optical element light emitting / receiving unit is complicated and large. Furthermore, in the labyrinth wall, it is insufficient to prevent the intrusion of ambient light, the flow resistance is increased, the inflow property of the naturally flowing smoke is reduced, and the smoke may reach the optical element light emitting and receiving unit. Have difficulty. The conventional labyrinth wall has a complicated structure and a large size.
According to the present invention, a smoke sensor that detects smoke in a short time can be provided.

It is the perspective view which looked at the smoke detector 1 of one Embodiment of this invention from the downward direction. It is the perspective view which looked at the smoke detector 1 from the upper direction. 1 is a front view of a smoke detector 1. FIG. 2 is a rear view of the smoke detector 1. FIG. 2 is a left side view of the smoke detector 1. FIG. 2 is a right side view of the smoke detector 1. FIG. 2 is a plan view of the smoke detector 1. FIG. 2 is a bottom view of the smoke detector 1. FIG. 3 is a front view of the attachment member 2. FIG. It is a left view of the attachment member 2. It is the perspective view which looked at the housing base | substrate 4 from the downward direction. 3 is a front view of a housing base 4. FIG. 4 is a left side view of the housing base 4. FIG. It is sectional drawing of the housing base | substrate 4 seen from the cut surface line JJ of FIG. 4 is a bottom view of the housing base 4. FIG. It is sectional drawing of the smoke detector 1 seen from the cut surface line BB of FIG. It is sectional drawing of the smoke sensor 1 seen from the cut surface line HH of FIG. It is sectional drawing of the smoke sensor 1 seen from the cut surface line FF of FIG. It is sectional drawing of the smoke sensor 1 seen from the cut surface line II of FIG. It is a disassembled perspective view which shows the exhaust guide member 50, the light shielding cover 70, etc. relevant to the detection space formation body 40 upside down. It is sectional drawing seen from the left side for demonstrating the smoke passage in the smoke sensor. FIG. 22A is a horizontal cross-sectional view showing light scattered by smoke in the detection region in the detection space formation body 40, and FIG. 22B is a light shielding space 121 for the light receiving element 113 in the detection space formation body 40. It is a horizontal sectional view for demonstrating the function of the light-shielding member 118 which forms a. 3 is a perspective view showing a partition member 30 and an introduction light shielding member 41. FIG. It is the perspective view which looked at the partition member 30 from the bottom. 3 is a front view of a partition member 30. FIG. 4 is a left side view showing an introduction light shielding member 41, a lead-out light shielding member 42, and an exhaust guide member 50. FIG. It is the perspective view which looked at the introductory shading member 41 and the derivation shading member 42 from the lower part near the back. It is the perspective view which looked at the derivation | leading-out light shielding member 42 and the exhaust guide member 50 from the downward direction near the front. 4 is a front view of an introduction light shielding member 41. FIG. 4 is a rear view of an introduction light shielding member 41. FIG. 4 is a bottom view of an 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. 4 is a perspective view of a light shielding cover 70. FIG. It is the perspective view which looked at the light shielding cover 70 from the downward direction. 3 is a front view of a light shielding cover 70. FIG. 3 is a perspective view of a housing body 5. FIG. 7 is a perspective view of a display piece 91. FIG. It is the perspective view seen from the downward direction of the display piece 91. FIG. It is sectional drawing which shows the state by which the display piece 91 was mounted | worn with the housing main body 5, and the indicator 90 was comprised. It is a block diagram which shows the electronic circuit apparatus 60 of the smoke detector 1. FIG. It is a flowchart explaining operation | movement of the processing circuit 62 with which the electronic circuit apparatus 60 of the smoke detector 1 is equipped. It is a graph which shows the time passage of the output voltage from the light receiving element 113 corresponding to the smoke density in the detection region 111. 7 is a waveform diagram for explaining the operation of the display element 92 of the indicator 90. FIG.

  FIG. 1 is a perspective view of a smoke detector 1 according to an embodiment of the present invention as viewed from below, FIG. 2 is a perspective view of the smoke detector 1 as viewed from above, and FIG. 4 is a front view, FIG. 4 is a rear view of the smoke detector 1, FIG. 5 is a left side view of the smoke detector 1, FIG. 6 is a right side view of the smoke detector 1, and FIG. FIG. 8 is a plan view of the sensor 1, and FIG. 8 is a bottom view of the smoke sensor 1. With reference to these drawings, the smoke detector 1 basically includes a mounting member 2 and a housing 3. The housing 3 has a rectangular column shape with a flat overall shape, a housing base 4 fixed to the mounting member 2, and a housing body 5 that protrudes outward from the housing base 4 by forming a step 7. Have The attachment member 2 is attached to the ceiling 6 of a building room where smoke is to be detected, using bolts 8 or the like.

  A plurality of intake ports 11 are formed in each of the four peripheral walls 10 of the housing base 4. The lower portion 21 of the housing body 5 includes a bulging portion 22 that is elongated in the front and rear direction of the front and back surfaces and bulges downward, and a concave portion 23 that is recessed upward on the left and right sides of the bulging portion 22. The outlet portion 22 and the recess portion 23 form an exhaust port 24 that faces the left and right outer sides. Smoke generated by the fire immediately rises and reaches the lower surface of the ceiling 6 and moves horizontally along the ceiling 6. Between the lower surface of the ceiling 6 and the step 7, the centrifugal fan 100 ( 21), the smoke is detected by the detection means 110 in the housing 3, and is forcibly discharged downward from the exhaust port 24. When smoke is detected by the detection means 110, the indicator 90 blinks or is continuously lit to emit light, and the occurrence of a fire is displayed.

  FIG. 9 is a front view of the mounting member 2, and FIG. 10 is a left side view of the mounting member 2. The mounting plate 81 of the mounting member 2 is formed with a pair of left and right projections 82 and a pair of left and right locking pieces 83 closer to the back side (left side in FIG. 10) than the projections 82. 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 viewed 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. 14 is a section line of FIG. FIG. 15 is a cross-sectional view of the housing base 4 as viewed from JJ, and FIG. 15 is a bottom view of the housing base 4. With reference to these drawings, a support piece (not shown) is formed on the upper surface of the upper plate 12 of the housing base 4 and is supported by being engaged with the engagement piece 83 of the mounting member 2. The upper plate 12 is formed with a clamping piece 13 that elastically clamps and positions the protrusions 82 of the mounting member 2 by surrounding through holes.

  An annular outward flange 14 that forms a step 7 is formed at the lower end of each peripheral wall 10, and a locking claw 15 that extends downward for removably connecting to the housing body 5 is formed. A line drawing port 16 is formed to hang downward from the outward flange 14. A storage recess 17 for storing 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 cross-sectional view of the smoke detector 1 as viewed from a cross-sectional line BB in FIG. 8, and FIG. 17 is a cross-sectional view of the smoke sensor 1 as viewed from a cross-sectional line H-H in FIG. 18 is a cross-sectional view of the smoke detector 1 as viewed from a cross-sectional line FF in FIG. 3, and FIG. 19 is a cross-sectional view of the smoke sensor 1 as viewed from a cross-sectional line II in 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. 21 is a diagram for explaining the smoke passage in the smoke detector 1. It is sectional drawing seen from the left side. With reference to these drawings, the partition member 30 is disposed on the housing base 4 with a spacer projection 88 spaced downward. The outward flange 14 of the housing base 4 is in contact with the left and right outer edges of the partition pieces 34 and 35 of the partition member 30. Thus, 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. In the air chamber 32, air forcedly sucked by the centrifugal fan 100 from the intake port 11 through the filter 87 is collected. In FIG. 17, the air flow is indicated by solid arrows. The centrifugal fan 100 has an inlet 101 that opens downward facing the air chamber 32, and discharges air from the inlet 101 from an outlet 102 that opens toward the front. The 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 includes an introduction light shielding member 41 and a lead-out 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 shielding member 41, an air shielding protrusion 89 formed on the lower surface of the upper plate 12 of the housing base 4, and the hanging A guide space 49 is formed by a U-shaped air guide protrusion 48 extending from the wall 47 to the back surface (left side in FIG. 21). The hanging wall 47 closes the air chamber 32 on both the left and right sides of the outlet 102 of the centrifugal fan 100.

  For example, the temperature detection element 127 that detects the temperature of the air is disposed in the air chamber 32 as an example.

  Air is supplied to the detection space 45 formed in the detection space forming body 40 from the inlet 43 near the upper back surface of the detection space 45. The air in the detection space 45 is led out from a lead-out port 44 formed in the lower plate 46 of the lead-out light shielding member 42 near the lower front of the detection space 45. The air from the outlet 44 passes through the 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 is inclined downward toward the rear side of the exhaust guide member 50. 21 (to the left in FIG. 21), and 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, the bulging portion 22 of the housing body 5 and the lower surface in the vicinity thereof. After passing through 55, the gas is discharged from the exhaust port 24 to the outside on the lower side.

  22 (1) is a horizontal sectional view showing scattered light due to smoke in the detection region 111 in the detection space forming body 40, and FIG. 22 (2) is a light shielding space for the light receiving element 113 in the detection space forming body 40. 12 is a horizontal sectional view for explaining the function of a light shielding member 118 forming 121. FIG. These FIG. 22 (1) and FIG. 22 (2) correspond to FIG. 19 described above.

  The detection unit 110 includes a detection space forming body 40. The detection space forming body 40 forms a light-blocking detection space 45 in the middle of a passage through which air containing smoke is sucked and pumped by the centrifugal fan 100. This detection space 45 has a smoke detection area 111. The detection space 45 is a rectangular shape formed by the partition plate 131 of the introduction light shielding member 41 and the hanging wall 47, 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 space of a body, for example, a rectangular parallelepiped. The introduction light shielding member 41 and the lead-out light shielding member 42 are made of a light shielding synthetic resin or the like, and at least the inner surface forming the detection space 45 may be black to suppress 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 back side. The light emitting element 112 generates light toward the detection region 111. A light receiving element holding portion 138 in which a recess for holding the light receiving element 113 from above is formed 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 region 111.

  The light emission path forming member 115 is light-shielding and hollow, is connected to the light emitting element holding portion 137 (FIG. 22) in the hanging wall 47, extends along the optical axis of the light emitting element 112, and is a light emitting element with respect to the detection region 111. A light emission path 114 indicated by an imaginary line along which light from the light emitting element 112 follows is formed near 112. The light emission path forming member 115 defines the spread along the light emission optical axis of the light emitted from the light emitting element 112 necessary for detecting smoke in the detection region 111 according to the directivity characteristic of the light emitting element 112, that is, the light emission optical axis is changed. A predetermined luminous intensity or illuminance range, for example, a directivity angle and a half-value angle, are defined on the circumference in the virtual vertical plane as the center, and the light intensity detection space unnecessary for smoke detection is defined. Limit radiation and suppress diffuse reflection.

  The light-receiving path forming member 117 is light-shielding and hollow, is connected to the light-receiving element holding portion 138 (FIG. 22) in the hanging wall 47, extends along the optical axis of the light-receiving element 113, and receives the light-receiving element with respect to the detection region 111. A light receiving path 116 indicated by an imaginary line along which light toward 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 detecting smoke from the detection region 111 according to the directivity characteristics of the light receiving element 113, and is not necessary for detecting smoke. The incident of irregularly reflected light from other than the detection region 111 is limited to prevent erroneous detection.

  Components corresponding to the light-emitting element holding part 137 and the light-receiving element holding part 138 of the lead-in light shielding member 41 are also provided below the lead-out light shielding member 42, and the same reference numeral is attached with a suffix a. These are combined vertically to perform the holding function.

  The light shielding member 118 serves as a light shielding space 121 in the vicinity of the optical axis of the light receiving element 113 and serves as a light shielding space 121, and includes a pair of light shielding plates 122 and 123, a partition plate 131, a lower plate 136, and side walls. 133. The light shielding space 121 extends along the optical axis of the light receiving element 113 to the opposite side of the light receiving element 113 with respect to the detection area 111, opens toward the detection area 111, and is away from the detection area 111. Now, it is closed by the side wall 133.

  The light shielding member 118 spreads the incident light of the light receiving element 113 at a position opposite to the light receiving element 113 on the side opposite to the light receiving element 113 with respect to the detection region 111 along the optical axis of the light receiving element 113, that is, light receiving sensitivity. Is obtained to be equal to or greater than a predetermined value. For example, the viewing angle extends so as to be covered.

  As shown in FIG. 22 (2), the light that is emitted from the light emitting element 112 in the detection space 45 by the light shielding member 118 is irregularly reflected regardless of how the light is irregularly reflected as indicated by the arrow. Since it does not reach the light receiving element 113 unless it enters the light shielding space 121 of 118, the irregularly reflected light reaching the light receiving element 113 can be reduced. The light that enters the light shielding space 121 of the light shielding member 118 has already weakened its energy, which is the amount of light, due to irregular reflection in the detection space 45, and therefore reaches the light receiving element 113 and enters the range indicated by the virtual line 119. Therefore, the reflected light is naturally weakened, and therefore, does not adversely affect the detection operation by the photocurrent of the light receiving element 113. Since the light shielding member 118 can be realized by a simple configuration such as a partition wall such as the light shielding plates 122 and 123, the components including the detection space forming body 40 and the light shielding member 118 are made of synthetic resin, thereby injection molding. Can simplify the mold.

  At the end of the light receiving path forming member 117 near the detection region 111, the light receiving path 116 of the light receiving element 113 is moved away from the light emitting element 112, and is moved up and down in the detection space 45 outside the light emitting path 114 of the light emitting element 112. A light-shielding projection 125 that extends and projects is provided. This protrusion 125 is outside the light emission path 114 of the light emitting element 112, and thus does not interfere with the spread of the light emitted from the light emitting element 112, which is necessary for smoke detection, to the detection area 111. It is certain to prevent the light irregularly reflected by the light 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 opposite side of the light emitting element 112, opens toward the detection area 111, is closed at a position away from the detection area 111, Another light shielding member can be further provided in which the range corresponding to the directivity around the optical axis of the light emitting element 112 is the light shielding space 121. Thereby, irregular reflection of light from the light emitting element 112 in the detection space 45 can be further prevented.

  FIG. 23 is a perspective view showing the partition member and the introduction light shielding member, FIG. 24 is a perspective view of the partition member viewed from below, and FIG. 25 is a front view of the partition member. With reference to these drawings, the rear end face of the U-shaped air guide protrusion 48 is U in the plan view standing on the partition plate 31 of the partition member 30 in the vicinity of the outlet 102 of the centrifugal fan 100. It fits into the letter-shaped shielding protrusion 33, abuts against the front surface of the shielding protrusion 33, and guides air to the introduction port 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 close the air chamber 32 between the housing base 4 and the upper plate 12 on both sides of the introduction light shielding member 41. On the partition plate 31, the guide piece 36 is suspended facing 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. FIG. 27 is a perspective view of the introduction light shielding member 41 and the lead-out light shielding member 42 as viewed from below near the back surface. FIG. 28 is a perspective view of the lead-out light shielding member 42 and the exhaust guide member 50 as seen from below, close to 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. 31 is a bottom view of the introduction light shielding member 41. FIG. 32 is a rear view of the derived light shielding member 42, and FIG. 33 is a plan view of the derived light shielding member 42.

  With reference to these drawings, the lead-out light shielding member 42 is formed with a partition plate 139 extending from the substantially middle position of the front wall 135 to the front side. The upper surface of the partition plate 139 forms a guide space between the partition pieces 34 and 35 of the partition member 30 and the lower surface of the upper plate 12 of the housing base 4, and the filter 87 in the peripheral wall 10 is connected to the front surface from the air inlet 11. The air passing through is guided to the air chamber 32 and overlaps the lower surface of the outward flange 14 on the front surface of the housing base 4. Engaging portions 141 and 142 extending inward and upward from each other 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, and both left and right sides of the hanging wall 47 of the introduction light shielding member 41. The lead-in light shielding member 41 and the lead-out light shielding member 42 are assembled by engaging with the ends. The left and right locking claws 151 and 152 of the lead-out light shielding member 42 are detachably locked with the locking recesses 56 and 57 of the exhaust guide member 50.

  FIG. 34 is a perspective view of the light shielding cover 70, FIG. 35 is a perspective view of the light shielding cover 70 as viewed from below, and FIG. 36 is a front view of the light shielding cover 70. 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, a connector 61 is disposed on the substrate 63 of the electronic circuit device 60 so as to face the connector wall 38 of the partition member 30, and the light emitting element 112, the light receiving element 113, and the temperature detecting element 127. Each flexible lead wire is 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. Then, a processing circuit 62 and the like realized by a microcomputer or the like for controlling those operations are provided. For example, the temperature detection element 127 is provided in the above-described air chamber 32 by inserting a lead wire thereof into a connection hole 39 formed in the partition member 30. The board 63 is fixed by screwing bolts 64 and 65 into the screw holes 86 (FIG. 24) of the partition member 30 and the screw holes 88 (FIG. 15) of the housing base 4.

  The light shielding cover 70 includes a lower plate 71, left and right side plates 72 and 73, a back 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 in series on the left and right when the assembly is completed. The lower plate 71 is formed with a through hole 79 through which the display element 92 is exposed downward.

  FIG. 37 is a perspective view of the housing body 5. A display piece 91 for the indicator 90 is fixed near the back surface 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 projections 27 are formed to which the locking claws 15 of the housing base 5 are detachably locked. A notch 29 for the line drawing port 16 is formed in the back 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 as viewed from below, and FIG. 40 is a cross-sectional view showing a state in which the display piece 91 is fixed to the housing body 5. With reference to these drawings, the display piece 91 has an annular protrusion 94 on the upper surface of a disk-shaped base portion 93, and the lower surface of the base portion 93 has an elongated and flat display protrusion on the front and back sides. Article 95 is included. The lower portion of the display protrusion 95 is formed in a downwardly convex arc shape in both the front-rear direction cross section and the left-right direction cross section. The display element 92 faces the concave portion of the annular projection 94 through the through hole 79 of the light shielding cover 70, and light from the display element 92 is irradiated. When the refractive index of the synthetic resin material of the housing body 5 and the display piece 91 is different, the light from the display element 92 propagates only to the display protrusion 95 of the display piece 91 and shines when viewed from below. Since it is obtained, aesthetics are improved.

  FIG. 41 is a block diagram showing a configuration of the electronic circuit device 60 of the smoke detector 1. The 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 the fan 100 is detected by the rotational speed detector 145 and is supplied to the processing circuit 62. The processing circuit 62 drives the light emitting element 112 by the light emission driving circuit 146. The output of the light receiving element 113 is given to the processing circuit 62 via the amplifier circuit 147. The communication terminal 67 of the connector 61 is connected to the processing circuit 62 via the communication circuit 148, whereby the processing circuit 62 can exchange signals with a remote display device or the like. The processing circuit 62 controls the lighting of the display element 92. A control power supply circuit 149 is provided. The detection unit 110 includes the detection space forming body 40 and the electronic circuit device 60 including detection circuits such as the light emitting element 112, the light receiving element 113, and the processing circuit 62.

  FIG. 42 is a flowchart for explaining the operation of the processing circuit 62 provided in the electronic circuit device 60 of the smoke detector 1. Moving from step s1 to step s2, the processing circuit 62 is initialized, and processing operation for the indicator 90 including the display element 92 is performed in step s3. In step s4, a processing operation for transmitting fire information is performed. In step s5, it is determined whether or not the time measured W by the smoke detection timer provided in the processing circuit 62 has exceeded a predetermined set time W0 (for example, 0.5 seconds). If not, the process returns to step s3. If it is determined in step s5 that the time period W has exceeded a predetermined setting time W0 of 0.5 seconds or more, the light emitting element 112 is turned on in step s6. In step s7, the light reception signal from the light receiving element 113 is taken into the processing circuit 62, and in step s8, the light emitting element 112 is turned off. In step s9, the smoke concentration is calculated from the output voltage level of the light receiving signal from the light receiving element 113, and the occurrence of a fire is determined. When it is determined that the output voltage of the light reception signal from the light receiving element 113 is equal to or higher than a predetermined threshold value corresponding to the detected smoke concentration and a fire has occurred, the display element 92 is set in a predetermined manner. For example, the occurrence of a fire is visually displayed by blinking or continuous lighting. If there is no fire, the display element 92 is kept off. In step s10, the time count W of the smoke detection timer is cleared to zero, and the process returns to step s3. In this way, the smoke concentration is detected every preset time W0.

  FIG. 43 is a graph showing the time lapse of the output voltage from the light receiving element 113 corresponding to the smoke concentration in the detection region 111. The output voltage of the light receiving element 113 corresponds to the concentration of smoke contained in the air passing through the detection region 111 in the detection space 45 of the detection space forming body 40. The processing circuit 62 responds to the output of the light receiving element 113 in step s9 of FIG. 42, and when the output voltage is equal to or higher than a predetermined threshold value indicated by the reference symbol L1, for example, a fire has occurred. Then, the display element 92 performs a display operation indicating the occurrence of a fire.

  FIG. 44 is a waveform diagram for explaining the operation of the display element 92 of the indicator 90. If the concentration of smoke contained in the air passing through the detection region 111 is low, and the output of the light receiving element 113 is less than the threshold value L1 in FIG. 92, the processing circuit 62 causes the lighting time W1 and the lighting time W2 in FIG. 44 to blink at regular intervals.

  If the smoke concentration is high and, therefore, the output of the light receiving element 113 is equal to or greater than the threshold value L1 in FIG. 43, the display element 92 is driven by the processing circuit 62 and has a different interval from the normal time (non-fire time). Is blinking. When the output of the light receiving element 113 becomes equal to or higher than the threshold value L1 at time t1, the display element 92 is turned on for the time W1 and turned off for the next time W2, unlike the normal time (non-fire). Such an operation is repeated.

  The processing circuit 62 is also responsive to the output of the temperature detection element 127, and when the detected air temperature is equal to or higher than a predetermined value at the time of the fire occurrence, the display element of the indicator 90 regardless of the smoke concentration. 92 is driven to display.

  In another embodiment, the processing circuit 62 may be continuously lit instead of the blinking operation of FIG. 44, or may be displayed by acoustic display or vibration instead of these visual displays. .

The following embodiments are possible for the present invention.
(1) (a) the housing 3,
An intake port 11 opening outward at the top 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) suction means 100 for sucking air from the intake port 11 and exhausting it through the passage to the exhaust port 24;
(C) A smoke detector including a detection means 110 provided in the middle of the passage and detecting smoke in the air.

  A smoke detector is provided that detects smoke in a short time. For example, smoke generated by a fire immediately rises to reach the lower surface of the ceiling 6, moves along the ceiling 6, and is present around the smoke detector 1 near the lower surface of the lower surface of the ceiling 6. Smoke at the initial stage of the occurrence of fire is sucked by suction means 100, for example, a centrifugal fan, forcibly sucked into the passage from the intake port 11 opened outward at the top of the housing 3 and led to detection means for detecting smoke in the air. However, the exhaust port 24 is forced to exhaust through the passage and does not stay in the passage. Therefore, the smooth inflow property of the smoke moving along the ceiling 6 to the detection means 110 is good, and the smoke can be detected promptly and reliably. Instead of the centrifugal fan, another configuration that sucks and pumps air may be used, or an axial fan or the like may be used.

  The air inlet 11 also includes a configuration in which the air inlet 11 faces the lower surface of the ceiling 6 with a space downward from the lower surface of the ceiling 6 at the upper portion of the housing 3 and opens directly upward or obliquely upward. The exhaust port 24 at the lower part of the housing 3 includes a configuration that opens directly below the housing 3, obliquely downward, or outward, and is disposed below the intake port 11.

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

  A smoke sensor 1 is provided that reliably prevents the intrusion of ambient light into the detection space 45 that optically detects scattered light from smoke. Intrusion of ambient light into the detection space 45 can be prevented with an easy structure. Since disturbance light from outside the installation space, for example, the room of the building, does not enter the detection space 45, there is no possibility of erroneous detection that smoke is present.

  The passage leading from the intake port 11 to the detection space 45 is bent at least once in all the directions of the three orthogonal directions of XYZ, that is, the direction in which the smoke flows is changed twice or more. For example, in the embodiment described later, the air from the left and right intake ports 11 moves in the horizontal X-axis direction (that is, the left-right direction) in the air chamber 32, and is then sucked into the inlet 101 of the centrifugal fan 100. The Z-axis direction air that has been sucked and lowered by the centrifugal fan 100 is moved from the outlet 102 of the centrifugal fan 100 to the front side. After moving in the Y-axis direction and the flow direction is changed once again, it is introduced into the detection space 45, so that air reaches the introduction port 43 of the detection space 45 from the left and right intake ports 11. Up to at least three axial directions.

  Even if external disturbance light enters the inlet end of the air inlet 11 without providing a light shielding wall such as the above-described conventional labyrinth wall in the smoke detector 1 incorporating the suction means 100, The disturbance light that has entered from the entrance end does not reach the detection space 45. Further, by not providing a light shielding wall having a complicated structure like the above-described conventional labyrinth wall, the structure of the passage becomes simple, the design and manufacture become easy, and the cost can be reduced.

  In another form of implementation, in the smoke detector 1 incorporating the suction means 100, either between the intake port 11 and the detection space 40, between the detection space 40 and the exhaust port 24, or both. A filter 87 having a porous structure may be attached. Thereby, in addition to smoke, for example, foreign matters such as dust and insects, or external disturbance light from the outside hardly enters the detection space 45. According to the present invention, the structure of the passage is simplified, and dust and insects can easily enter, but foreign matter disturbance light and the like by the filter 87 can be prevented. The filter 87 may be made of porous, for example, a sintered metal, a synthetic resin, a nonwoven fabric, paper or the like having a three-dimensionally complicated communication hole, may be elastic, and may be 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;
A lead-out port 44 through which air from the detection space is led to the passage,
The detection region 111 is arranged in the middle of the air path from the inlet 43 to the outlet 44.

  Within the detection space 45, there are a smoke detection region 111, a light blocking member 118 for preventing irregular reflection, a protrusion 125, and the like.

  Since the detection region 111 is disposed in the middle of the air path from the inlet 43 to the outlet 44, the air is constantly flowing and does not stay, so that the detection of smoke is quick.

(4) The detection means 110
A light-blocking detection space 45 is formed in the middle of the passage, and a detection space forming body 40 having a smoke detection region 111 in the detection space 45,
A light emitting element 112 that generates 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 region 111;
Along the optical axis of the light receiving element 113, the detection region 111 extends to the opposite side of the light receiving element 113, opens toward the detection region 111, is closed at a position away from the detection region 111, and is on the optical axis of the light receiving element 113. A light shielding member 118 having a light shielding space in a range corresponding to the directivity characteristic in the periphery (the light shielding member 118 may include 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 that responds to the output of the light receiving element 113 and detects that the output corresponds to smoke.

  The structure for preventing diffuse reflection of light in the detection space 45 for optically detecting light scattered by smoke is simplified, miniaturized, and an inexpensive smoke detector 1 is provided.

  The light receiving element 113, for example, a silicon photodiode, has a viewing angle or a half-value angle, and the sensitivity outside the viewing angle is low with respect to the front surface that is within the viewing angle. In the present invention, the spread of incident light of the light receiving element 113 at a position opposite to the light receiving element 113 on the side opposite to the light receiving element 113 with respect to the detection region 111 along the optical axis of the light receiving element 113, for example, is described later. As shown in the light receiving path 116 of 22 (1), a light shielding member 118 extending so as to cover and wrap the viewing angle is provided. The light shielding member 118 opens toward the detection region 111, is closed at a position away from the detection region 111, and defines a range corresponding to the directivity around the optical axis of the light receiving element 113 as the light shielding space 121.

  Even if the light emitted from the light emitting element 112, for example, the light emitting diode, is irregularly reflected in the detection space 45 by the light shielding member 118, the irregularly reflected light does not enter the light shielding space 121 of the light shielding member 118. Then, since the light does not reach the light receiving element 113, the irregularly reflected light reaching the light receiving element 113 can be reduced as shown in FIG. The light that enters the light shielding space 121 of the light shielding member 118 has already weakened its energy, which is the amount of light, due to irregular reflection in the detection space 45, so that the reflected light that reaches the light receiving element 113 is naturally weakened. Therefore, the detection operation by the photocurrent of the light receiving element 113 is not adversely affected. Since the light shielding member 118 can be realized with a simple configuration such as a partition wall, if the constituent 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 of light from the light-emitting element 112 near the light-emitting element 112 with respect to the detection region 111;
And a light-blocking light-receiving path forming member 117 that extends along the optical axis of the light-receiving element 113 and forms a light-receiving path 116 of light to the light-receiving element 113 near the light-receiving element 113 with respect to the detection region 111. .

  The light emission path forming member 115 defines the spread along the light emission optical axis of the light emitted from the light emitting element 112 necessary for detecting smoke in the detection region 111 according to the directivity characteristics of the light emitting element 112. A predetermined luminous intensity or illuminance range, for example, a directivity angle and a half-value angle, is defined on the circumference in a virtual vertical plane centered on the emission optical axis, and low intensity light that is unnecessary for smoke detection is specified. Limits radiation to the detection space and suppresses diffuse reflection.

  The light receiving path forming member 117 stipulates the spread of incident light along the light receiving optical axis of the light receiving element 113 necessary for detecting smoke from the detection region 111 according to the directivity characteristics of the light receiving element, and is unnecessary for detecting smoke. The incident of irregularly reflected light from other than the detection region 111 is limited 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 opposite side of the light emitting element 112, opens toward the detection area 111, is closed at a position away from the detection area 111, Another light shielding member can be further provided in which the range corresponding to the directivity around the optical axis of the light emitting element 112 is a light shielding space. Thereby, irregular reflection of light from the light emitting element 112 in the detection space 45 can be further prevented.

  (6) Detection is performed outside the light emission path 114 of the light emitting element 112 at a position away from the light emitting element 112 with respect to the light receiving path 116 of the light receiving element 113 at the end of the light receiving path 116 near the detection region 111. A light-shielding protrusion 125 protruding into the space 45 is provided.

  The protrusion 125 is located outside the light emission path 114 of the light emitting element 112, and thus does not interfere with the spread of light necessary for smoke detection to the detection region 111 of the light emitted from the light emitting element 112, without interfering with the detection space 45. It is certain to prevent the irregularly reflected light from entering the light receiving element 113.

(7) A temperature detecting element 127 for detecting the temperature of the air is provided in the middle of the passage,
The detection means not only detects smoke but also responds to the temperature output of the temperature detection element 127 and detects that the temperature output corresponds to a fire.

  By detecting both smoke and the temperature of air that may contain smoke, it is possible to quickly detect the occurrence of a fire or the like. The temperature detection element 127, for example, the thermistor, may be disposed upstream of the suction unit 100, that is, closer to the intake port 11 than the suction unit 100.

(8) Smoke detector for preventing irregular reflection that may not be forced suction,
A light-shielding detection space 45 is formed in the middle of the air passage, and a detection space forming body 40 having a smoke detection region 111 in the detection space 45;
A light emitting element 112 that generates 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 region 111;
Along the optical axis of the light receiving element 113, the detection region 111 extends to the opposite side of the light receiving element 112, opens toward the detection region 111, is closed at a position away from the detection region 111, and is on the optical axis of the light receiving element 112. A light shielding member 118 having a light shielding space 121 as a range corresponding to directivity at the periphery;
The smoke detector includes a detection circuit 60 that responds to an output of the light receiving element 113 and detects that the output corresponds to smoke.

  As described above, there is provided a smoke detector 1 that simplifies and miniaturizes the structure for preventing diffused reflection of light in the detection space 45 that optically detects light scattered by 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 surface within the viewing angle. In the present invention, the spread of incident light of the light receiving element 113 at a position opposite to the light receiving element 113 on the side opposite to the light receiving element 113 with respect to the detection region 111 along the optical axis of the light receiving element 113, for example, is described later. As shown in the light receiving path 116 of 22 (1), a light shielding member 118 extending so as to cover and wrap the viewing angle is provided. The light shielding member 118 opens toward the detection region 111, is closed at a position away from the detection region 111, and defines a range corresponding to the directivity around the optical axis of the light receiving element 113 as the light shielding space 121.

  Even if the light emitted from the light emitting element 112, for example, the light emitting diode, is irregularly reflected in the detection space 45 by the light shielding member 118, the irregularly reflected light does not enter the light shielding space 121 of the light shielding member 118. Then, since the light does not reach the light receiving element 113, the irregularly reflected light reaching the light receiving element 113 can be reduced as shown in FIG. The light that enters the light shielding space 121 of the light shielding member 118 has already weakened its energy, which is the amount of light, due to irregular reflection in the detection space 45, so that the reflected light that reaches the light receiving element 113 is naturally weakened. Therefore, the detection operation by the photocurrent of the light receiving element 113 is not adversely affected. Since the light shielding member 118 can be realized with a simple configuration such as a partition wall, if the constituent 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 intake port, an exhaust port, and a passage for guiding air from the intake port to the exhaust port;
(B) suction means for sucking air from the intake port, forcibly exhausting to the exhaust port through the passage;
(C) provided in the middle of the passage, and detecting means for detecting smoke in the air,
(D) At least one of a passage from the intake port to the introduction port of the detection space formation member and a passage from the discharge port of the detection space formation member to the exhaust port is:
The smoke detector is light-shielding and is formed by bending in at least three axial directions along the air flow direction.

  According to the present invention, a smoke sensor that detects smoke in a short time is provided. The smoke at the initial stage of the fire is sucked into the passage from the intake port 11 of the housing 3 by being forced by the suction means 100, for example, a centrifugal fan, and is guided to the detection means for detecting smoke in the air. 24 is forced to exhaust and does not stay in the passage. Therefore, the smooth inflow property to the smoke detection means 110 is good, and the smoke can be detected promptly and reliably. Instead of the centrifugal fan, another configuration that sucks and pumps air may be used, 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 introduction port 43 of the detection space forming body 40 and the passage from the outlet port 44 to the exhaust port 24 of the detection space forming body 40 is light-shielding, A smoke detector 1 is provided that is formed to bend in at least three axial directions along the flow direction, so that disturbance light can be reliably prevented 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 an easy structure. Since disturbance light from outside the installation space, for example, the room of the building, does not enter the detection space 45, there is no possibility of erroneous detection that smoke is present.

  The passage leading from the intake port 11 to the detection space 45 is bent at least once in all the directions of the three orthogonal directions of XYZ, that is, the direction in which the smoke flows is changed twice or more. As an example, the configuration in which the centrifugal fan 100 is used to bend air in at least three axial directions is as described above.

  Even if external disturbance light enters the inlet end of the air inlet 11 without providing a light shielding wall such as the above-described conventional labyrinth wall in the smoke detector 1 incorporating the suction means 100, The disturbance light that has entered from the entrance end does not reach the detection space 45. Further, by not providing a light shielding wall having a complicated structure like the above-described conventional labyrinth wall, the structure of the passage becomes simple, the design and manufacture become easy, and the cost can be reduced.

(10) (a) the housing 3,
An intake port 11 opening outward at the top 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) suction means 100 for sucking air from the intake port 11 and forcibly exhausting it through the passage to the exhaust port 24;
(C) The heat sensor 1 includes a detecting means 127 provided in the middle of the passage and detecting the temperature of the air.

  A heat sensor is provided that detects the temperature of the air in a short time. For example, air that may contain smoke generated by a fire immediately rises to reach the lower surface of the ceiling 6, moves along the ceiling 6, and near the lower surface of the ceiling 6 near the lower surface of the heat sensor. The smoke at the initial stage of the occurrence of a fire is forced into the passage by the suction means 100 and sucked by the suction means 100 that opens outward at the upper part of the housing, and is guided to the detection means 127 that detects the temperature of the air. The gas is forcibly exhausted to the exhaust port 24 through the passage and does not stay in the passage. Therefore, the smooth inflow property of the air moving along the ceiling 6 to the detection means 127 is good, and the temperature of the air can be detected promptly and reliably. The temperature of air generated by other than fire is also detected.

  The air inlet 11 also includes a configuration in which the air inlet 11 faces the lower surface of the ceiling 6 with a space downward from the lower surface of the ceiling 6 at the upper portion of the housing 3 and opens directly upward or obliquely upward. The exhaust port 24 at the lower part of the housing 3 includes a configuration that opens directly below the housing 3, obliquely downward, or outward, and is disposed below the intake port 11.

(11) A light-shielding detection space 45 is formed in the middle of a passage through which a fluid containing fine particles is supplied, and a detection space forming body 40 having a fine particle detection region 111 in the detection space 45;
A light emitting element 112 that generates 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 region 111;
Along the optical axis of the light receiving element 113, the detection region 111 extends to the opposite side of the light receiving element 113, opens toward the detection region 111, is closed at a position away from the detection region 111, and is on the optical axis of the light receiving element 113. A light shielding member 118 having a light shielding space 121 as a range corresponding to directivity at the periphery;
And a detection circuit 60 for detecting that the output corresponds to the fine particles in response to the output of the light receiving element 113.

  When detecting fine particles contained in a fluid such as air or a fluid such as liquid, for example, smoke in the air, the diffused reflection of light in the detection space 45 for optically detecting scattered light by the fine particles is prevented as described above. An apparatus for detecting particulates in a fluid is provided that simplifies the structure for miniaturization.

  The present invention can be implemented not only in connection with smoke detectors, but also in connection with thermal detectors, and further includes particulates contained in gases or liquids as well as smoke in the air. Can be implemented in a wide range of technical fields.

DESCRIPTION OF SYMBOLS 1 Smoke detector 3 Housing 4 Housing base body 5 Housing main body 6 Ceiling 11 Air inlet 18 Filter holding protrusion 22 Bulging part 24 Exhaust port 30 Partition member 32 Air chamber 40 Detection space formation body 41 Introducing light shielding member 42 Deriving light shielding member 43 Inlet port 44 Outlet 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 blocking member 121 Light blocking space 127 Temperature detection element 137, 137a Light emitting element holding part 138, 138a Light receiving element holding part

Claims (6)

In the smoke detector that sucks ambient air from the intake port by a blower provided in the housing, supplies it to the detection area in the detection means for optically detecting smoke in the air, and discharges it from the exhaust port.
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
A smoke detector formed by bending in at least three axial directions along the air flow direction.   The smoke sensor according to claim 1, further comprising a filter having a porous structure in at least one of a passage from the intake port to the detection region and a passage from the detection region to the exhaust port. By a blower provided in the housing, the surrounding air is sucked in from the upper side or the upper side surface, and the sucked air is discharged from the lower side or the lower side surface.
A fire detector comprising a detecting means for detecting a fire by the sucked air.   The fire detector according to claim 3, wherein the detection means for detecting a fire outputs a fire information signal or a fire signal corresponding to a physical phenomenon serving as a reference for determining a fire by the sucked air. .   The fire detector according to claim 3 or 4, wherein the detection means for detecting a fire includes a plurality of fire detection means. A light-shielding detection space is formed in the middle of the air passage, and a smoke detection area is provided in this detection space.
A light emitting element for generating light toward the detection region;
A light receiving element having an optical axis that intersects the optical axis of the light emitting element in the detection region;
Along the optical axis of the light receiving element, the detection area extends to the opposite side of the light receiving element, opens toward the detection area, is closed at a position away from the detection area, and supports directional characteristics around the optical axis of the light receiving element. A smoke detector including a light shielding member having a light shielding space in the range.