JP7394360B2 - Detector and fire alarm system - Google Patents

Description

TECHNICAL FIELD The present disclosure generally relates to a sensor and a fire alarm system , and more particularly to a sensor and a fire alarm system that detect smoke generated by, for example, a fire.

Patent Document 1 discloses a combined heat and smoke sensor. This sensor includes a heat sensing means that senses heat, and a smoke sensing section (smoke detection chamber) that senses smoke that has flowed into the dark box. The heat sensing means includes a lead wire connected to the circuit board and protruding upward from the circuit board, and a heat sensitive element such as a thermistor provided at the upper end of the lead wire. Further, the smoke detection section is composed of a dark box, and a light emitting means and a light receiving means arranged inside the dark box, and detects scattered light when the light emitted from the light emitting means is scattered by smoke flowing into the dark box. Smoke is detected by the light receiving means receiving light.

Incidentally, the sensor is sometimes installed in an environment where steam is likely to enter the smoke detection room (for example, in a dressing room near a bathroom). The sensor disclosed in Patent Document 1 may mistakenly detect steam as smoke.

Japanese Patent Application Publication No. 2012-14330

The present disclosure has been made in view of the above reasons, and aims to provide a sensor and a fire alarm system that can reduce the possibility of false detection occurring.

A sensor according to one aspect of the present disclosure includes a smoke detection chamber, an opening, and a dividing section. The smoke detection chamber has an inlet through which smoke flows. The opening allows communication between an external space and a space around the smoke detection chamber. The dividing portion is arranged in the surrounding space so as to surround the smoke detection chamber, and divides the gas flow path. The dividing portion is configured to have a first inflow amount of smoke flowing into the gas flow path from the opening and a second inflow amount of steam flowing into the gas flow path from the opening. the flow of the gas such that a first ratio of the amount of smoke reaching the inlet to the inflow of 1 is higher than a second ratio of the amount of steam reaching the inlet to the second inflow; Split the road.
A sensor according to one aspect of the present disclosure includes a smoke detection chamber, an opening, and a dividing section. The smoke detection chamber has an inlet through which smoke flows. The opening allows communication between an external space and a space around the smoke detection chamber. The dividing portion is arranged in the space around the smoke detection chamber and divides the gas flow path. The dividing portion forms a first space, a second space, and a third space in the gas flow path. The external space and the first space, the first space and the second space, and the second space and the third space are adjacent to each other in one direction from the opening toward the smoke detection chamber. The dividing portion is configured to have a first inflow amount of smoke flowing into the gas flow path from the opening and a second inflow amount of steam flowing into the gas flow path from the opening. the flow of the gas such that a first ratio of the amount of smoke reaching the inlet to the inflow of 1 is higher than a second ratio of the amount of steam reaching the inlet to the second inflow; Split the road. Regarding the first inflow amount of smoke and the second inflow amount of steam, in the third space, the first proportion of the smoke is higher than the second proportion of the steam. In the cross section along the one direction and the vertical direction, the cross-sectional area of the second space is larger than the cross-sectional area of each of the first space and the third space.
A sensor according to one aspect of the present disclosure includes a smoke detection chamber, a base, a cylindrical portion, an opening, and a dividing portion. The smoke detection chamber has an inlet through which smoke flows. The base has the smoke detection chamber mounted thereon. The cylindrical portion is arranged to cover the lower surface of the base. The opening allows communication between an external space and a space around the smoke detection chamber. The dividing portion is arranged in the space around the smoke detection chamber and divides the gas flow path. The base has a protruding edge that protrudes outward from the cylindrical portion. The dividing portion is configured to have a first inflow amount of smoke flowing into the gas flow path from the opening and a second inflow amount of steam flowing into the gas flow path from the opening. the flow of the gas such that a first ratio of the amount of smoke reaching the inlet to the inflow of 1 is higher than a second ratio of the amount of steam reaching the inlet to the second inflow; Split the road.
A sensor according to one aspect of the present disclosure includes a smoke detection chamber, an upper cover, an opening, and a dividing section. The smoke detection chamber has an inlet through which smoke flows. The upper cover is arranged to cover the smoke detection chamber from above. The opening allows communication between an external space and a space around the smoke detection chamber. The dividing portion is arranged in the space around the smoke detection chamber and divides the gas flow path. The dividing section includes a branching section that divides the space around the smoke detection chamber into two in a separation direction including a vertical component and branches into two, an upper flow path and a lower flow path. The branch portion causes smoke that has passed through the upper channel of the upper channel and the lower channel to flow into the smoke detection chamber from the inlet. The upper cover forms a part of the upper flow path of the upper flow path and the lower flow path. The dividing portion is configured to have a first inflow amount of smoke flowing into the gas flow path from the opening and a second inflow amount of steam flowing into the gas flow path from the opening. the flow of the gas such that a first ratio of the amount of smoke reaching the inlet to the inflow of 1 is higher than a second ratio of the amount of steam reaching the inlet to the second inflow; Split the road.
A fire alarm system according to one aspect of the present disclosure includes the sensor and a receiver that communicates with the sensor.

FIG. 1 is a cross-sectional view of a sensor according to a first embodiment. FIG. 2 is an external perspective view of the same sensor. FIG. 3 is an exploded perspective view of the sensor seen from above. FIG. 4 is an exploded perspective view of the sensor seen from below. FIG. 5 is a perspective view of the same sensor as seen from above, excluding a part of the upper cover. FIG. 6 is an exploded perspective view of the sensor of FIG. 5 with the cover of the smoke detection chamber removed. FIG. 7 is a block diagram of the same sensor. FIG. 8 is a perspective view of Modified Example 1 of the same sensor as seen from above excluding the upper cover. FIG. 9 is a perspective view of Modified Example 2 of the same sensor as seen from above, excluding a part of the upper cover. FIG. 10 is a sectional view of a main part of a third modification of the above sensor. FIG. 11 is a plan view of a modified example of the base in the above sensor. FIG. 12 is a cross-sectional view of the sensor according to the second embodiment. FIG. 13 is a perspective view of the same sensor as seen from above, excluding a part of the upper cover. FIG. 14 is an exploded perspective view of the sensor seen from below. FIG. 15A is a diagram for explaining the responsiveness of the sensor to the taper angle of the inclined portion of the sensor. FIG. 15B is a diagram for explaining the responsiveness of the sensor to the taper angle in the airflow control section of the same sensor. FIG. 15C is a diagram for explaining the responsiveness of the sensor to the thickness of the airflow control section of the sensor. FIG. 16 is a sectional view of a main part of a modified example of the above sensor having a protrusion. FIG. 17 is a sectional view of a main part of a modified example in which the airflow control section of the above sensor has a curved taper. FIG. 18 is a sectional view of a main part of a modified example of the above sensor having a restriction section. FIG. 19 is a sectional view of a main part of a modified example in which the taper of the dividing portion of the above sensor is flat.

(Overall overview)
Hereinafter, an overview of the sensors (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the present disclosure will be explained.

The sensor according to the present disclosure is, for example, a fire sensor, and has a function of detecting (fire) smoke generated by a fire or the like. The sensor according to the present disclosure is a photoelectric sensor. Although the sensor according to the present disclosure will be described below assuming that it is a scattered light type sensor, it is not limited to the scattered light type and may be a transmitted light type sensor.

Further, in the following description, it is assumed that the sensor according to the present disclosure is a so-called composite fire sensor that has a function of detecting heat generated by a fire or the like in addition to a smoke detection function. However, the sensor according to the present disclosure does not need to have a heat detection function. As shown in FIG. 2, the sensor according to the present disclosure is installed, for example, on a construction surface 100 (ceiling surface in the illustrated example) such as a ceiling surface or a wall surface of a building.

The sensor according to the present disclosure includes a smoke detection chamber 4, an opening 510, and a dividing portion Z1. The smoke detection chamber 4 has an inlet 40 through which smoke flows. The opening 510 communicates the external space SP2 with the space SP1 around the smoke detection chamber 4. The dividing part Z1 is arranged in the space SP1 around the smoke detection chamber 4, and divides the gas flow path 6. The dividing part Z1 has a first inflow amount of smoke flowing into the gas flow path 6 from the opening 510 and a second inflow amount of steam flowing into the gas flow path 6 from the opening 510. dividing the gas flow path such that a first ratio of the amount of smoke reaching the inlet 40 to the inflow amount is higher than a second ratio of the amount of steam reaching the inlet 40 to the second inflow amount; do. As shown in FIGS. 3 and 13, the divided portion Z1 is arranged in a space SP1 around the smoke detection chamber 4, and is formed over the entire circumference of the smoke detection chamber 4.

Here, for example, in Embodiment 1 below, the dividing part Z1 controls the first inflow amount of smoke flowing into the gas flow path 6 from the opening 510 in the upper flow path 61, and the first inflow amount of smoke flowing into the gas flow path 6 from the opening 510. With respect to the second inflow amount of steam flowing into the flow path 6, the first ratio of the amount of smoke reaching the inlet 40 to the first inflow amount is equal to the second inflow amount of steam reaching the inlet 40 relative to the second inflow amount. This corresponds to being higher than the second proportion of the amount. For example, in the second embodiment below, in the third space SP5, the first inflow amount of smoke flowing into the gas flow path 6 from the opening 510 and the first inflow amount of smoke flowing into the gas flow path 6 from the opening 510 With respect to the second inflow amount of steam, the first ratio of the amount of smoke that reaches the inlet 40 to the first inflow amount is the second ratio of the amount of steam that reaches the inlet 40 to the second inflow amount. This corresponds to being higher than .

Moreover, if the "first ratio of the amount of smoke" is higher than the "second ratio of the amount of steam", it can be said that the dividing part Z1 divides the gas flow path 6. The dividing portion Z1 does not necessarily correspond to dividing the gas flow path 6 so as to completely separate smoke and steam. For example, if smoke with a volume flow rate of A [cm ³ /sec] flows into the opening 510 and smoke with a volume flow rate of B [cm ³ /sec] flows into the inlet 40, the first ratio is It becomes B/A. When steam with a volumetric flow rate A [cm ³ /sec] that is the same as the volumetric flow rate of the smoke described above flows into the opening 510, it is assumed that steam with a volumetric flow rate C [cm ³ /sec] flows into the inlet 40. Then, the second ratio becomes C/A. In this case, the dividing portion Z1 means dividing the gas flow path 6 so that, for example, (B/A)>(C/A) holds.

By the way, when comparing smoke and steam, smoke particles have a smaller particle diameter than steam particles, and furthermore, smoke particles have a lighter weight than steam particles. Therefore, when smoke and steam are compared, smoke particles have a higher diffusion force and a smaller inertial force than steam particles. Utilizing this difference between smoke and steam, the dividing part Z1 divides the space into a space through which smoke can easily pass and a space through which steam can easily pass.

According to this configuration, smoke particles having a higher dispersion force and a smaller inertial force than steam particles can easily flow into the smoke detection chamber 4 due to the dividing part Z1, while steam particles can easily flow into the smoke detection chamber 4. It becomes difficult for people to flow in. That is, the airflow containing smoke flows into the smoke detection chamber 4 from the inflow port 40 due to the dividing portion Z1. As a result, the sensors (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the present disclosure have the advantage of being able to reduce the possibility of false detection occurring.

(Embodiment 1)
(1) Overview As shown in FIG. 1, the sensor 1 according to the present embodiment includes a smoke detection chamber 4 and a divided portion Z1. The division part Z1 includes a branch part 71.

The smoke detection chamber 4 has an inlet 40 through which smoke flows. The branch portion 71 is arranged around the smoke detection chamber 4 . The branching part 71 divides the space SP1 around the smoke detection chamber 4 into two in a separation direction A1 including a vertical direction A2 component, and divides the gas flow path 6 into two, an upper flow path 61 and a lower flow path 62. Branch (divide).

The branching portion 71 is configured to cause smoke that has passed through the upper flow path 61 of the upper flow path 61 and the lower flow path 62 to flow into the smoke detection chamber 4 from the inflow port 40 . That is, the branching part 71 included in the dividing part Z1 branches (divides) the gas flow path 6 into two, the upper flow path 61 and the lower flow path 62. In the upper channel 61, the first ratio of the amount of smoke reaching the inlet 40 to the inflow amount is higher than the second ratio of the amount of steam reaching the inlet 40 to the second inflow amount. .

According to this configuration, smoke particles that tend to rise easily pass through the upper channel 61, while steam particles having a larger mass than the smoke particles easily pass through the lower channel 62. In other words, there is a high possibility that only smoke will flow into the smoke detection chamber 4 from the inlet 40 due to the branch portion 71 . As a result, the sensor 1 has the advantage of reducing the possibility of false detection occurring.

By the way, in this embodiment, in addition to the smoke detection chamber 4, the sensor 1 further includes at least one (here, two as an example) airflow control walls 8 (see FIG. 5). The smoke detection chamber 4 has an inlet 40 through which smoke flows. An airflow control wall 8 is arranged around the smoke detection chamber 4 . The airflow control wall 8 controls the airflow so as to reduce variations in smoke inflow into the smoke detection chamber 4 in the circumferential direction A3 of the smoke detection chamber 4. Here, "the variation in smoke inflow property is small" means that smoke can enter the sensor 1 from any direction within 360 degrees around the sensor 1 (through the opening 510) when looking at the sensor 1 in the vertical direction. This means that even if smoke enters the smoke detection chamber 4, the difference in the amount flowing into the smoke detection chamber 4 is small.

According to this configuration, by controlling the airflow by the airflow control wall 8, variations in smoke inflow into the smoke detection chamber 4 are reduced. Therefore, the sensor 1 has the advantage of being able to improve smoke inflow into the smoke detection chamber 4.

(2) Details (2.1) Overall configuration The overall configuration of the sensor 1 according to this embodiment will be described in detail below. As described above, the sensor 1 is a composite fire sensor that detects smoke and heat.

In the following, the vertical direction of the sensor 1 will be defined and explained using the up and down arrows shown in FIG. 2, which shows the state in which the sensor 1 is installed on the construction surface 100 (ceiling surface). This arrow is merely shown for the purpose of assisting the explanation and has no substance. Further, this direction is not intended to limit the direction in which the sensor 1 is used.

The sensor 1 includes the smoke detection chamber 4 (smoke detection section) described above. The sensor 1 further includes a base 2, a housing 5, and a flow path forming member 7, as shown in FIGS. 1 and 3 to 6. The sensor 1 further includes a heat detection section 3, a control section 9, and a display section 10, as shown in FIG. The sensor 1 further includes a disk-shaped mounting base that is fixed to the construction surface 100 by screws or the like. The sensor 1 can be installed on the construction surface 100 by having a mounting portion provided on the upper surface side of the casing 5 removably attached to the mounting base.

The detector 1 further includes a communication unit 11 (see FIG. 7) that transmits a signal notifying the occurrence of a fire to an external alarm device, etc., and receives a signal from an alarm device, etc. when a fire is detected. ing.

The sensor 1 may be supplied with power by a commercial power supply, or may be supplied with power by a battery provided inside the housing 5.

(2.2) Housing The housing 5 accommodates the base 2, the heat detection section 3, the smoke detection chamber 4, the control section 9, the display section 10, the communication section 11, and other circuit modules, etc. . Furthermore, the housing 5 supports one surface of the guide portion of the display section 10 so as to be exposed to the outside.

The housing 5 is made of synthetic resin, for example, flame-retardant ABS resin. The housing 5 as a whole is formed into a cylindrical shape that is flat in the vertical direction. As shown in FIGS. 3 and 5, the casing 5 includes a cylindrical lower cover 51 (front cover) with one side (top surface in the illustrated example) open, and a substantially disc-shaped upper cover 52 (back cover). It has . The housing 5 is constructed by assembling the upper cover 52 to the lower cover 51 from one open side thereof. The upper cover 52 is arranged to cover the smoke detection chamber 4 from above. The lower cover 51 is arranged below the base 2.

The housing 5 also includes a flow path 6 provided in the internal space SP1 through which gas flows, and one or more (six in this case) openings 510 (horizontal holes) connecting the flow path 6 and the external space SP2. It has . Here, a plurality of openings 510 are provided in the lower cover 51. In other words, the lower cover 51 has an opening 510 that communicates the external space SP2 with the space SP1 around the smoke detection chamber 4.

Specifically, as shown in FIGS. 2 and 3, the lower cover 51 includes a flat cylindrical body 51A with both upper and lower ends open, and a disc-shaped base 51B located below the cylindrical body 51A. It is composed of a plurality of (for example, six) pillars 51C that connect the cylindrical body 51A and the base 51B. The cylindrical body 51A, the base 51B, and the six pillars 51C are integrally formed. The six pillars 51C are arranged at approximately equal intervals along the circumferential direction at the peripheral edge of the base 51B, and protrude from the peripheral edge toward the open lower edge of the cylindrical body 51A. The six pillars 51C maintain the distance between the cylindrical body 51A and the base 51B at a specified distance. The six openings 510 are arranged at approximately equal intervals along the circumferential direction (corresponding to the circumferential direction A4 of the sensor 1) on the circumferential wall of the lower cover 51 configured in this manner.

Each opening 510 is a substantially rectangular through hole that penetrates the peripheral wall of the lower cover 51 in the radial direction, and serves as an opening that connects the flow path 6 and the external space SP2.

The base 51B has a positioning structure for positioning the base 2 on its upper surface. Here, a cylindrical portion 511 is provided as the positioning structure (see FIGS. 1 and 3). In other words, the sensor 1 of this embodiment further includes the cylindrical portion 511 arranged to cover the lower surface (second surface 22) of the base 2. The cylindrical portion 511 protrudes in a cylindrical shape from the upper surface of the base portion 51B. The upper end surface of the cylindrical portion 511 contacts the lower surface of the base 2.

The lower cover 51 has a pair of holes (not shown in FIG. 2) in the base 51B for exposing one surface (lower surface) of the guide portion of the display section 10 to the external space SP2. Therefore, the light emitted from the pair of light sources 10A (see FIG. 4) of the display section 10 is guided to the outside of the housing 5 through the pair of guide sections, respectively.

The upper cover 52 has a plurality of insertion holes into which a plurality of connection pieces of a mounting portion fixed to the base 2 are inserted. The plurality of connection pieces are electrically connected to a circuit module provided on the base 2. The plurality of connection pieces are inserted to such an extent that their tips sufficiently protrude from the back side of the upper cover 52. The plurality of connection pieces can be mechanically and electrically connected to contact portions of the mounting base fixed to the construction surface 100. In short, the mounting part is not only a mechanical connection to the mounting base, but also an electrical connection to the electric wires (power supply line and signal line) on the back side of the ceiling, and a stable connection of the base 2 to the upper cover 52. This part also serves as positioning.

Further, the upper cover 52 has an accommodation recess 521 (see FIG. 4) on one surface (lower surface) facing the base 2 for accommodating the upper part of the smoke detection chamber 4 mounted on the base 2. The housing recess 521 is formed by the entire center portion of the upper cover 52 protruding upward. The smoke detection chamber 4 is stably positioned by the accommodation recess 521.

Here, the sensor 1 further includes a pair of airflow control walls 8, as shown in FIG. Here, as an example, the airflow control wall 8 is formed as a part of the upper cover 52. The pair of airflow control walls 8 are provided outward from the accommodation recess 521 on one surface (lower surface) of the upper cover 52 that faces the base 2 . The pair of airflow control walls 8 are arranged around the smoke detection chamber 4 and control the airflow so as to reduce variations in smoke inflow into the smoke detection chamber 4 in the circumferential direction A3 of the smoke detection chamber 4. A detailed description of the airflow control wall 8 will be given later.

(2.3) Base The base 2 is configured such that the smoke detection chamber 4 is mounted thereon. Here, as an example, the base 2 is a circuit board. The base 2 is, for example, a single printed wiring board provided with conductor pattern wiring. As shown in FIGS. 3 and 4, the base 2 has a pair of engagement holes 27 passing through the base 2 in its thickness direction. The pair of engagement pieces 42 (see FIG. 4) provided on the body 4B of the smoke detection chamber 4 are inserted into and hooked into the pair of engagement holes 27, respectively, so that the smoke detection chamber 4 is connected to the second section of the base 2. It is attached to one surface 21 (upper surface). Note that the flow path forming member 7 is held in such a manner that it is sandwiched between the smoke detection chamber 4 and the base 2 from above and below.

Furthermore, in addition to the smoke detection chamber 4, the base 2 is equipped with a heat detection section 3, a control section 9, a display section 10, a communication section 11, and other circuit modules. Other circuit modules include a lighting circuit that lights up the light source 10A of the display unit 10 and the optical element 401 of the smoke detection chamber 4 (see FIGS. 6 and 7), and various circuits that use power supplied from a commercial power source, etc. Includes power supply circuits that generate operating power for the circuits.

As shown in FIGS. 3 and 4, the base 2 is formed into a substantially circular shape as a whole. In this embodiment, one or more (six in FIG. 5) heat detection elements 30 of the heat detection unit 3 are arranged on the outer peripheral portion 23 of the base 2. The six heat sensing elements 30 are surface mounted on the first surface 21 (upper surface) of the base 2. Here, as an example, the smoke detection chamber 4 is also arranged on the first surface 21 of the base 2. Hereinafter, the surface of the base 2 opposite to the first surface 21 may be referred to as the second surface 22 (lower surface). The light source 10A of the display unit 10 is mounted on the second surface 22 of the base 2, as shown in FIG.

Of the first surface 21 and the second surface 22, the first surface 21 corresponds to the surface closer to the construction surface 100. Therefore, it can be said that the heat detection element 30 and the smoke detection chamber 4 are both arranged on the surface of the base 2 that is closer to the construction surface 100.

The control unit 9 and a plurality of electronic components constituting the circuit module are mounted on the first surface 21 or the second surface 22 of the base 2. The control unit 9 and the plurality of electronic components constituting the circuit module do not need to be mounted only on the base 2; for example, another mounting board may be arranged around the base 2, and the electronic components constituting the circuit module may be mounted on the base 2. Some or all of them may be implemented.

The structure of the base 2 will be described in detail below. As shown in FIG. 5, the base 2 includes a circular main body 20 (the part inside the dashed line) and a plurality of circular main body parts 20 (in the illustrated example) extending in a direction away from the center of the main body 20 at the edge of the main body 20. It has a total of 12 extension parts. The smoke detection chamber 4 is arranged at the center of the upper surface of the main body 20.

The twelve extending portions are composed of six protruding edges 25 and six tongues 26. The outer peripheral portion 23 of the base 2 described above is a portion corresponding to the six protruding edges 25 and the six tongue portions 26.

Each tongue portion 26 is a portion where a corresponding one of the six heat sensing elements 30 is mounted. Each tongue portion 26 has an upper surface and a lower surface that are flush with and continuous with the upper surface and lower surface of the main body portion 20, respectively. Each tongue portion 26 projects from the main body portion 20 in the shape of an elongated strip when viewed in the vertical direction, and its tip portion is formed in a semicircular shape. The six tongue parts 26 are arranged at equal intervals along the circumferential direction of the main body part 20 so as to divide the outer peripheral part 23 of the base 2 into approximately six equal parts. Each heat sensing element 30 is mounted near the tip on the upper surface of the corresponding tongue portion 26 . The tongue portion 26 has a through hole 260 having a rectangular opening in a region inside the heat sensing element 30 . By providing the through holes 260 near each heat detection element 30, the area occupied by the base 2 around the heat detection element 30 can be reduced. As a result, the heat in the heat detection element 30 is transmitted through the base 2 and becomes lower, or the heat generated by other circuit components mounted on the main body 20 affects the heat detection element 30. Possibility can be reduced. That is, the through holes 260 improve thermal insulation. The opening area of the through hole 260 is desirably larger than the surface area of the heat sensing element 30 (for example, the surface area viewed from above the base 2).

Each protruding edge 25 has an upper surface and a lower surface that are flush with and continuous with the upper surface and lower surface of the main body 20, respectively. Each of the protruding edges 25 is in the form of a strip, curved along an arc with the central axis of the main body 20 as the center of the circle, when viewed along the up-down direction. The six protruding edges 25 are lined up along the circumferential direction of the main body 20. A corresponding one of the six tongues 26 is arranged between two adjacent protruding edges 25. In other words, the six tongue portions 26 and the six protruding edges 25 are alternately arranged one by one along the circumferential direction of the main body portion 20 .

Each protruding edge 25 of this embodiment is configured to protrude outward from the cylindrical portion 511, as shown in FIG. In other words, when viewed along the vertical direction, the projected area of the main body portion 20 is approximately the same as the cylindrical portion 511, and the six protruding edges 25 protrude from the cylindrical portion 511. Note that the amount of protrusion of the tongue portion 26 with respect to the main body portion 20 is slightly larger than the amount of protrusion of the protruding edge portion 25.

Incidentally, the outer circumferential portion 23 of the base 2 has a recess 24 (see FIG. 5) that is recessed inward in a peripheral area where the heat sensing element 30 is arranged. Here, a total of 12 recesses 24 are provided so that a pair of recesses 24 corresponds to each of the six tongues 26. Specifically, a pair of recesses 24 are formed on both sides in the circumferential direction of the main body 20 of each tongue 26 on which the heat sensing element 30 is mounted.

Therefore, each tongue portion 26 is arranged between two adjacent protruding edges 25 so as to leave a gap between each of the two protruding edges 25 . Therefore, the hot air caused by the fire can be efficiently guided to the heat detection element 30 on the tongue 26 by the recess 24. That is, heat flow properties are improved. In addition, the heat in the heat detection element 30 may be transmitted through the base 2 and the heat generated in other circuit components on the main body 20 may be transferred to the heat detection element 30 on the tongue part 26 via the protruding edge 25. This can reduce the possibility of adverse effects.

As described above, the base 2 of this embodiment has, for example, a six-fold symmetrical shape that becomes symmetrical by rotating 60 degrees around its center.

(2.4) Heat Detection Unit and Smoke Detection Unit As described above, the heat detection unit 3 has six heat detection elements 30 mounted on the first surface 21 of the base 2 (in FIG. 7, one (only one shown). The number of heat detection elements 30 is not particularly limited, and may be one, but preferably at least two or more. The heat detection element 30 is a chip thermistor that detects the heat of the gas flowing in from the opening 510, and is surface mounted on the base 2. Each heat sensing element 30 is arranged to face one different opening 510.

The heat detection section 3 is electrically connected to the control section 9 via pattern wiring formed on the base 2 or the like. Each heat detection element 30 outputs an electric signal (detection signal) to the control unit 9. In other words, the control unit 9 monitors the resistance value of each heat detection element 30, which can change depending on the temperature rise, through the electrical signal output from each heat detection element 30.

In addition to the heat detection element 30, the heat detection unit 3 may further include an amplification circuit that amplifies the electrical signal from the heat detection element 30, a conversion circuit that performs analog-to-digital conversion, or the like, or the amplification and conversion may be performed. , may be performed on the circuit module side.

The smoke detection chamber 4 is arranged in the center of the internal space of the housing 5 and is configured to detect smoke. Specifically, the smoke detection chamber 4 is arranged on the upper surface of the main body part 20 of the base 2, and the upper part thereof is housed in the accommodation recess 521 of the upper cover 52. The smoke detection chamber 4 is, for example, a photoelectric sensor that detects smoke, particularly a scattered light sensor.

As shown in FIGS. 6 and 7, the smoke detection chamber 4 includes an optical element 401 that emits light, a light receiving element 402 that receives the light emitted from the optical element 401, and a labyrinth part 403. There is. The optical element 401 is, for example, an LED (Light Emitting Diode). The light receiving element 402 is, for example, a photodiode. The labyrinth portion 403 is formed inside a housing having a flat, substantially cylindrical outer contour.

The housing of the smoke detection chamber 4 is constructed by assembling a cover 4A and a body 4B. As shown in FIG. 6, the cover 4A has a flat, substantially cylindrical outer shell with an open bottom surface. The cover 4A has a plurality of inlets 40 on its outer peripheral surface that allow gas to flow into the labyrinth portion 403. Fire smoke flows into the labyrinth part 403 from the inlet 40. Each inlet 40 has a substantially rectangular opening when viewed from the front. The plurality of inflow ports 40 are arranged side by side along the circumferential direction A3 of the smoke detection chamber 4. In addition, in this embodiment, the circumferential direction A3 of the smoke detection chamber 4 coincides with the circumferential direction A4 of the sensor 1.

The body 4B is formed in a substantially disk shape, and has a structure on its upper surface that suppresses external light from entering the body, and a structure that holds the optical element 401 and the light receiving element 402. The body 4B also has a pair of engagement pieces 42 (see FIG. 4) that protrude downward from its lower edge. The pair of engagement pieces 42 are inserted into the pair of insertion holes 74 of the flow path forming member 7, and further inserted and hooked into the pair of engagement holes 27 of the base 2, so that the smoke detection chamber 4 It is attached to the base 2 in such a manner that the flow path forming member 7 is sandwiched between the flow path forming member 7 and the base 2.

The optical element 401 and the light receiving element 402 are arranged in the labyrinth portion 403 so as not to face each other. In other words, the light receiving surface of the light receiving element 402 is arranged so as to be off the optical axis of the light irradiated by the optical element 401.

When a fire or the like occurs, fire smoke enters the housing 5 through the opening 510 of the housing 5 and can be further introduced into the labyrinth portion 403 through the inlet 40. When there is no smoke within the labyrinth portion 403, the irradiated light from the optical element 401 hardly reaches the light receiving surface of the light receiving element 402. On the other hand, if smoke exists within the labyrinth portion 403, the light emitted from the optical element 401 is scattered by the smoke, and a portion of the scattered light reaches the light receiving surface of the light receiving element 402. That is, in the smoke detection chamber 4, the light receiving element 402 receives the irradiated light from the optical element 401 that is scattered by smoke.

The light receiving element 402 of the smoke detection chamber 4 is electrically connected to the control section 9. The smoke detection chamber 4 transmits to the control unit 9 an electric signal (detection signal) indicating a voltage level according to the amount of light received by the light receiving element 402. The control unit 9 converts the light intensity of the detection signal received from the smoke detection chamber 4 into smoke density and determines whether there is a fire. The control unit 9 may use the light amount as it is for threshold determination. The smoke detection chamber 4 may convert the amount of light received by the light receiving element 402 into smoke density, and then transmit a detection signal indicating a voltage level according to the smoke density to the control unit 9.

The smoke detection chamber 4 may further include an amplification circuit that amplifies the electrical signal from the light receiving element 402 and a conversion circuit that converts analog to digital, or the amplification and conversion may be performed on the circuit module side. Good too. Further, the number of optical elements 401 for smoke detection is not limited to one, and may be plural.

(2.5) Display section The display section 10 has a pair of light sources 10A and a pair of guide sections. Each light source 10A is configured, for example, as a packaged LED in which at least one LED chip is mounted in the center of the mounting surface of a flat mounting board. Each light source 10A is mounted on the base 2 as described above. Each guide portion is a translucent portion. Each guide portion faces the corresponding light source 10A on the base 2 and has an entrance surface onto which light emitted from the light source 10A enters. Each guide portion has an output surface through which light that has entered from the input surface is output to the outside of the guide portion. The output surface of each guide portion is exposed through a corresponding hole in the lower cover 51.

The display unit 10 is an operating light that notifies the outside of the operating state of the sensor 1. During normal times (when monitoring a fire), the lighting circuit of the circuit module turns off the light source 10A under the control of the control unit 9. When it is determined that a fire has occurred, the lighting circuit of the circuit module starts blinking or lighting the light source 10A under the control of the control unit 9. In FIG. 7, illustration of a lighting circuit between the control section 9 and the display section 10 is omitted.

(2.6) Control Unit The control unit 9 can be realized by, for example, a computer system including one or more processors (microprocessors) and one or more memories. That is, one or more processors function as the control unit 9 by executing one or more programs (applications) stored in one or more memories. Although the program is pre-recorded in the memory of the control unit 9 here, it may also be provided via a telecommunications line such as the Internet or by being recorded on a non-temporary recording medium such as a memory card.

The control unit 9 is configured to control the communication unit 11 and circuit modules (such as a lighting circuit and a power supply circuit).

Further, the control unit 9 is configured to receive detection signals from the heat detection unit 3 and the smoke detection chamber 4 and determine whether or not a fire has occurred. Specifically, the control unit 9 individually monitors the detection signals from the six heat detection elements 30 of the heat detection unit 3, and determines whether the signal level (corresponding to the resistance value) included in the detection signal exceeds the threshold value. (or below) If even one heat detection element 30 is found, it is determined that a fire has occurred. The control unit 9 also monitors the detection signal from the smoke detection chamber 4, and if the signal level included in the detection signal (corresponding to the amount of light received by the light receiving element 402 or the smoke density) exceeds a threshold, a fire is detected. It is determined that this has occurred.

When the control unit 9 determines that a fire has occurred based on heat detection or smoke detection, the control unit 9 transmits a signal notifying the occurrence of a fire to the receiver of the automatic fire alarm system, the fire alarm, etc. via the communication unit 11. do. The communication unit 11 is a communication interface for communicating with a receiver, a fire alarm, etc., for example by wire. The communication section 11 is communicably connected to a receiver, a fire alarm, etc. via a connection piece of the mounting section, a connector section of the mounting base, and a signal line wired on the back side of the ceiling. Further, when the control unit 9 determines that a fire has occurred, it outputs a control signal for blinking or lighting the light source 10A of the display unit 10 (operating light) to the lighting circuit of the circuit module.

(2.7) Channel-forming member The channel-forming member 7 in this embodiment is made of synthetic resin, for example, flame-retardant ABS resin. The flow path forming member 7 has a flat, generally cylindrical outer shell with an open upper surface. Specifically, the flow path forming member 7 has a base portion 70, a branch portion 71 (divided portion Z1), and a blocking portion 72, as shown in FIGS. 3 and 4.

The base 70 has a disk shape. The base 70 has a pair of insertion holes 74 passing through the base 70 in its thickness direction. As described above, the pair of engagement pieces 42 of the smoke detection chamber 4 can be inserted through the pair of insertion holes 74, respectively.

The blocking portion 72 is a cylindrical portion that is continuously formed so as to protrude upward from the outer peripheral edge of the base portion 70 . In a state where the smoke detection chamber 4 is attached to the base 2 with the flow path forming member 7 sandwiched between the base 2 and the base 2, the smoke detection chamber 4 is located in a recess 75 ( (see Figure 3). With the smoke detection chamber 4 accommodated in the recess 75, the peripheral wall 41 of the smoke detection chamber 4 is generally covered by the blocking portion 72 with a predetermined gap X1 (see FIGS. 1 and 6) from the blocking portion 72. be exposed.

The branch portion 71 is a substantially annular portion that is continuously formed from the upper edge of the blocking portion 72 . Specifically, the branching portion 71 is formed to extend outward in the radial direction of the blocking portion 72 from the upper end edge of the blocking portion 72 and further protrude downward. As a result, the upper edge of the flow path forming member 7 as a whole has a "curved shape". The branch portion 71 is formed over the entire upper edge of the blocking portion 72 in the circumferential direction. With the smoke detection chamber 4 housed within the recess 75, the branch portion 71 is arranged around the smoke detection chamber 4.

The branching part 71 of this embodiment divides the space SP1 around the smoke detection chamber 4 into two in a separation direction A1 including a vertical direction A2 component, and divides the gas flow path 6 into an upper flow path 61 and a lower flow path 62. Branch (divide) into two parts. The branch portion 71 (divided portion Z1) is configured to cause the smoke that has passed through the upper channel 61 to flow into the smoke detection chamber 4 from the inlet 40. Here, the space SP1 is roughly divided into two in the vertical direction by the branching part 71. That is, the separation direction A1 generally coincides with the vertical direction A2. However, the separation direction A1 may be a direction intersecting the vertical direction A2 as long as it includes the vertical direction A2 component.

Specifically, the space SP1 is surrounded by the upper cover 52, the base 2, and the smoke detection chamber 4. The upper flow path 61 is a flow path surrounded by the upper cover 52 and the branch portion 71, and is a crank-shaped flow path in the cross-sectional view of FIG. In other words, the upper cover 52 forms a part of the upper channel 61. Therefore, compared to the case where the member forming the upper channel 61 is provided separately from the upper cover 52, the number of parts can be reduced. Further, it becomes easier to reduce the size of the sensor 1 (particularly, reduce its height).

Further, the lower flow path 62 is a straight flow path that is located below the upper flow path 61 and runs along the first surface 21 (upper surface) of the base 2 . In FIG. 1, the upper flow path 61 and the lower flow path 62 are schematically shown with arrows to make it easier to understand the direction in which the gas flows. Further, in FIG. 1, the upper flow passage 61 and the lower flow passage 62 are indicated by arrows only on the left side of the smoke detection chamber 4, but the upper flow passage 61 and the lower flow passage 62 are arranged in the circumferential direction of the smoke detection chamber 4. It is formed over almost the entire circumference at A3.

Here, the mass of the steam particles is greater than the mass of the smoke particles. By providing the branching part 71 (dividing part Z1), smoke particles, which tend to rise more easily than steam particles, enter through the opening 510 and then move toward the upper channel 61 rather than the lower channel 62. It becomes easier to pass dominantly. Therefore, the smoke particles easily overcome the branching part 71 (divided part Z1) and flow into the smoke detection chamber 4 from the inlet 40 on the back side of the blocking part 72. On the other hand, steam particles having a larger mass than smoke particles enter through the opening 510 and then pass through the lower flow path 62 more easily than the upper flow path 61. In other words, there is a high possibility that only smoke will flow into the smoke detection chamber 4 from the inlet 40 due to the branch portion 71 (divided portion Z1). As a result, the sensor 1 has the advantage of being able to reduce the possibility of false detections such as erroneously determining steam as fire smoke.

In particular, in the case of the sensor 1, since the space SP1 around the smoke detection chamber 4 is divided into two, there is a possibility that false detections may occur even though the external size of the sensor 1, which is relatively thin (low height), is maintained. can be reduced.

Further, as shown in FIG. 1, the blocking section 72 is disposed between the lower flow path 62 and the smoke detection chamber 4, and prevents steam passing through the lower flow path 62 from entering the smoke detection chamber 4. configured to block inflow. Therefore, the steam that is dominantly easier to pass through the lower flow path 62 than the upper flow path 61 due to the provision of the branch portion 71 has a higher possibility of colliding with the blocking portion 72. As a result, it becomes difficult for steam to flow into the smoke detection chamber 4, and the occurrence of false detection can be further suppressed. In particular, since the upper edge of the flow path forming member 7 has a "curved shape" as described above, the steam rises due to the reaction when it collides with the blocking part 72, climbs over the blocking part 72, and reaches the blocking part 72. It is possible to suppress the possibility that the water will reach the inlet 40 on the back side.

Further, as described above, the base 2 of this embodiment has the (six) protruding edges 25 that protrude from the cylindrical portion 511. Therefore, when steam entering from the opening 510 passes through the flow path 6A schematically indicated by the arrow in FIG. can be suppressed. In short, the protruding edge 25 can block the rise of steam.

Further, the protruding edge portion 25 protrudes so as to ensure a longer flow path length of the lower flow path 62. The longer the flow path length of the lower flow path 62 is, the easier it is to maintain straight movement due to the inertia of the steam particles, which are larger than the mass of the smoke particles. Therefore, by providing the protruding edge 25 on the base 2, it is possible to ensure a longer flow path length of the lower flow path 62, further reducing the proportion of steam rising midway and heading toward the upper flow path 61. be able to.

In this way, the rising steam is blocked by the protruding edge 25 and the straightness of the steam is maintained, so that the possibility that the steam passes through the upper flow path 61 can be reduced.

In addition, in this embodiment, the outer peripheral part 23 (here, the protruding edge part 25 and the tongue part 26) of the base 2 is arranged so that it does not protrude from the opening part 510 into the external space SP2 when the lower cover 51 is viewed from the front. It is composed of Therefore, it is possible to reduce the possibility that the outer peripheral portion 23 of the base 2 will obstruct smoke from entering into the sensor 1 from the opening 510.

(2.8) Airflow Control Wall By the way, in the peripheral wall 41 of the smoke detection chamber 4 of this embodiment, there is a region where the smoke inflow port 40 is not formed and smoke is difficult to flow into the inside of the smoke detection chamber 4. do. Here, the opposing wall 405 (see FIG. 6) of the cover 4A of the smoke detection chamber 4 corresponds to an area into which smoke is difficult to enter. When the cover 4A is assembled to the body 4B, the opposing wall 405 faces the outer surface of the holding block 404 (see FIG. 6) that holds the optical element 401 of the body 4B. In short, in the sensor 1 of this embodiment, the holding block 404 that holds the optical element 401 is arranged near the outer circumference of the body 4B, so the structure makes it difficult to arrange the inlet 40 on the outer surface side of the holding block 404. It becomes.

Below, in the peripheral wall 41 of the smoke detection chamber 4, the area where the inlet 40 is formed may be referred to as a first area 411, and the area where the inlet 40 is not formed may be referred to as a second area 412. (See Figure 5). That is, the peripheral wall 41 includes a first region 411 and a second region 412. The opposing wall 405 corresponds to the second region 412.

As described above, the smoke detection chamber 4 of this embodiment includes two (a pair) of airflow control walls 8 (see FIGS. 5 and 6). Each airflow control wall 8 is a substantially rectangular plate-shaped portion, and extends slightly beyond the outer edge of the protruding edge portion 25 of the base 2 from the peripheral wall 41 of the smoke detection chamber 4 when viewed along the vertical direction. It extends to the position of Further, each airflow control wall 8 is arranged so that its thickness direction is parallel to the tangential direction of the substantially circular base 2. 5 and 6, only two airflow control walls 8 of the upper cover 52 are shown in cross section.

As shown in FIG. 1, each airflow control wall 8 includes an L-shaped first portion 81 and a rectangular second portion 82 when viewed along its thickness direction. The first portion 81 is arranged to match the upper surface and outer circumferential surface of the branch portion 71 of the flow path forming member 7 . The second portion 82 is arranged such that the inner corner of its upper end substantially coincides with the outer corner of the lower end of the L-shaped first portion 81 . The lower end of the second portion 82 contacts the first surface 21 of the base 2 (mainly the upper surface of the protruding edge 25).

Each airflow control wall 8 also has a groove 80 at a position corresponding to the lower flow path 62. The groove portion 80 is provided to release steam that may predominantly pass through the lower flow path 62. The groove portion 80 is constituted by a lower end portion of a first portion 81, a second portion 82, and an inner side portion. With the airflow control wall 8 in contact with the base 2 and the flow path forming member 7, the groove portion 80 has a first portion 81, a second portion 82, This is a substantially rectangular opening surrounded by the base 2 and the flow path forming member 7.

As shown in FIGS. 5 and 6, the two airflow control walls 8 of this embodiment are arranged in the circumferential direction A3 of the peripheral wall 41 so that the second region 412 is sandwiched between them. As shown in FIG. 5, this corresponds to the range of the second region 412 (opposing wall 405) in the circumferential direction A3, centered on the center point P1 of the smoke detection chamber 4 when viewed from above. The first angle θ1 is approximately 40 degrees. Further, the second angle θ2 corresponding to the range between the two airflow control walls 8 in the circumferential direction A3 centered on the center point P1 is about 120 degrees. That is, the second angle θ2 is, for example, about three times the first angle θ1. In other words, the two airflow control walls 8 are each arranged at a certain angle (approximately 40 degrees here) from the second region 412 in the circumferential direction A3. Note that the numerical values regarding these angles are just examples and are not particularly limited.

Each airflow control wall 8 arranged around the smoke detection chamber 4 in this manner controls the airflow so as to reduce variations in smoke inflow into the smoke detection chamber 4 in the circumferential direction A3. Specifically, even if smoke that has entered from the external space SP2 toward the second region 412 collides with the second region 412 and is repelled along the circumferential direction A3, it is prevented from colliding with each airflow control wall 8. The air can be guided to the inlet 40 near the airflow control wall 8 (see airflow B1 indicated by the arrow in FIG. 5).

In particular, the first portion 81 of the airflow control wall 8 is provided at a position corresponding to the upper flow path 61. Therefore, as explained in the section "(2.7) Flow path forming member", the branch portion 71 allows the smoke to predominantly pass through the upper flow path 61, but the smoke passes through the upper flow path 61 along the circumferential direction A3. The smoke flowing and escaping can be efficiently collided with the first portion 81 and guided to the inlet 40.

By providing the airflow control wall 8 in this way, smoke can enter the sensor 1 from any direction within the 360 degrees surrounding the sensor 1 through the opening 510 (see FIG. 5). ), the difference in the amount that finally flows into the smoke detection chamber 4 can be small. As a result, the sensor 1 has the advantage of being able to improve the flow of smoke into the smoke detection chamber 4. Furthermore, since the airflow control wall 8 is formed as a part of the upper cover 52, the airflow control wall 8 can be stably positioned with respect to the second region 412 when the sensor 1 is assembled.

The number of airflow control walls 8 is not particularly limited, and may be one. However, as in this embodiment, the two airflow control walls 8 are arranged with the second region 412 in between in the circumferential direction A3, so that both of the smoke collided in the second region 412 and separated to the left and right are It can be efficiently guided to the inflow port 40. Therefore, the possibility that it becomes difficult for smoke to flow into the inside of the smoke detection chamber 4 can be further reduced.

Note that, as explained in the section "(2.7) Flow path forming member", the branch part 71 (divided part Z1) of the flow path forming member 7 allows steam to predominantly pass through the lower flow path 62. However, there is a possibility that the air collides with the airflow control wall 8, climbs over the branch part 71, and passes through the upper flow path 61. However, in this embodiment, as described above, the groove portion 80 is provided at a position corresponding to the lower flow path 62. Therefore, the steam flowing in the lower flow path 62 along the circumferential direction A3 easily passes through the groove portion 80 of the airflow control wall 8. As a result, the possibility that the steam collides with the airflow control wall 8, climbs over the branch portion 71, and passes through the upper channel 61 can be reduced.

By the way, the branch part 71 (divided part Z1) of this embodiment is not formed over the entire circumference of the smoke detection chamber 4, but has a notch 73 (see FIGS. 3 to 6). The cutout 73 is provided at a position facing the second region 412. Here, the notch 73 is formed to extend not only to the branch portion 71 (divided portion Z1) but also to the blocking portion 72. That is, both the branching part 71 (divided part Z1) and the blocking part 72 are partially missing in the circumferential direction A3 due to the notch 73, and have a substantially C-shape when viewed along the up-down direction. The width dimension of the notch 73 in the circumferential direction A3 is approximately equal to that of the second region 412. That is, when the notch 73 is viewed from the front, substantially the entire second region 412 is exposed.

By providing the cutout 73 in this way, smoke that has entered the sensor 1 toward the second region 412 can pass between the peripheral wall 41 of the smoke detection chamber 4 and the blocking portion 72 through the cutout 73. The airflow easily enters the gap X1 between the two (see the airflow B2 indicated by the arrow in FIG. 5). Therefore, the possibility that smoke becomes difficult to flow into the smoke detection chamber 4 can be further reduced.

In particular, the flow path forming member 7 prevents steam from entering the smoke detection chamber 4, but since the second region 412 exists, there is no need for the branch section 71 and the blocking section 72 in that part. , steam heading toward the second region 412 is likely to be blocked by the second region 412. Conversely, if in addition to the presence of the second region 412, the branch portion 71 and the blocking portion 72 are present in that portion, the inflow of smoke will be synergistically obstructed. From these viewpoints, the provision of the cutout 73 improves smoke inflow.

(2.9) Installation orientation By the way, it will be explained that the flow path forming member 7 of the sensor 1 is provided with a notch 73 at a position facing the second region 412 in consideration of smoke inflow. did. Here, for example, when the sensor 1 is installed in an environment where steam easily enters the smoke detection chamber 4 (for example, a changing room near a bathroom), the sensor 1 may be installed with the notch 73 side facing the bathroom side. If installed on the construction surface 100, there is a high possibility that steam will be allowed to flow in.

Therefore, the sensor 1 further includes a mark M1 that indicates the installation direction in the circumferential direction A4 of the sensor 1 when the sensor 1 is installed on the construction surface 100 (see FIGS. 2 to 6). The mark M1 is provided, for example, on the cylindrical body 51A of the lower cover 51. The mark M1 is a linear mark along the vertical direction, but the shape of the mark is not particularly limited. In this embodiment, as an example, a mark M1 is provided at a position corresponding to the notch 73 in the circumferential direction A4 of the sensor 1. In other words, the mark M1 is arranged so that a virtual line segment connecting the mark M1 and the center point P1 of the smoke detection chamber 4 when viewed from above passes through the notch 73. In other words, it can be said that the mark M1 indicates the direction related to the notch 73.

The mark M1 may be printed directly on the lower cover 51, or a printed sticker may be attached to the lower cover 51. Alternatively, the mark M1 may be a recess or a projection formed on the surface of the lower cover 51.

The installer who installs the sensor 1 can easily prevent the notch 73 from facing toward the bathroom by installing the sensor 1 on the construction surface 100 with the mark M1 facing away from the bathroom. It can be avoided. Therefore, the sensor 1 can be installed so that the specific area (the area where the notch 73 is present) in the circumferential direction A4 of the sensor 1 does not face a specific place (bathroom).

The mark M1 may be provided at a position corresponding to an area where the notch 73 does not exist. In this case as well, it can be said that the mark M1 indicates the direction related to the notch 73. The builder can easily prevent the cutout 73 from facing toward the bathroom by installing the sensor 1 on the construction surface 100 with the mark M1 facing toward the bathroom. Therefore, the sensor 1 can be installed such that the specific area (the area where the cutout 73 does not exist) in the circumferential direction A4 of the sensor 1 faces a specific place (bathroom).

(3) Modifications The above embodiment is just one of various embodiments of the present disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objective of the present disclosure can be achieved.

Modifications of the above embodiment will be listed below. The modified examples described below can be applied in combination as appropriate. Below, the above embodiment may be referred to as a "basic example".

In the basic example, the sensor 1 is equipped with an airflow control wall 8 . However, the airflow control wall 8 is not an essential component for the sensor 1 of the present disclosure, and may be omitted as appropriate. For example, FIG. 8 shows a sensor 1A of modification example 1. The sensor 1A includes a flow path forming member 7 having a notch 73 and a base 2 having a protruding edge 25, similarly to the sensor 1 of the basic example. However, the sensor 1A differs from the basic example sensor 1 in that it does not include the airflow control wall 8. This sensor 1A can also reduce the possibility of false detection occurring.

In the basic example, the flow path forming member 7 of the sensor 1 has a notch 73. However, the cutout 73 is not an essential component for the sensor 1 in the present disclosure. For example, FIG. 9 shows a sensor 1B of a second modification. The sensor 1B includes an airflow control wall 8 and a base 2 having a protruding edge 25, similar to the sensor 1 of the basic example. However, the branch portion 71A of the sensor 1B is different from the sensor 1 of the basic example in that it is formed over the entire circumference of the smoke detection chamber 4. Also in this sensor 1B, it is possible to improve the smoke inflow into the smoke detection chamber 4. Furthermore, the possibility of false detection occurring can be reduced. Further, in the sensor 1B, steam is difficult to flow into the smoke detection chamber 4 no matter which direction of 360 degrees it enters into the sensor 1.

In the basic example, the notch 73 is formed across both the branch part 71 and the blocking part 72. However, the cutout 73 may be formed only in the branch portion 71. In other words, the cutout 73 may be formed only at a position corresponding to the upper channel 61.

In the basic example, the branch part 71 (divided part Z1) of the flow path forming member 7 of the sensor 1 has a cross-sectional shape bent at a right angle in an L-shape (see FIG. 1). However, the shape of the branch portion 71 (divided portion Z1) is not particularly limited. For example, FIG. 10 shows a sectional view of a main part of a sensor 1C according to modification 3. The flow path forming member 7 of the sensor 1C is different from the sensor 1 of the basic example in that it has a branch portion 71B (divided portion Z1) having an inclined surface 76. The inclined surface 76 is inclined in a direction closer to the base 2 as it is further away from the upper end of the blocking portion 72 outward. Therefore, smoke particles can more easily overcome the branch part 71B through the inclined surface 76 than in the sensor 1 of the basic example, and can more easily flow into the smoke detection chamber 4 from the inlet 40 on the back side of the blocking part 72.

In this example, the base 2 of the sensor 1 has a protruding edge 25 . However, the protruding edge 25 is not an essential component for the sensor 1 in the present disclosure. As shown in FIG. 11, the sensor 1 may include a base 2A that does not have any protruding edge 25 and only has a main body 20 and six tongues 26. In FIG. 11, for ease of comparison, the protruding edge 25 that the base 2 of the sensor 1 of the basic example had is illustrated with a chain double-dashed line. In FIG. 11, illustration of the heat detection element 30 is omitted.

In the basic example, the number of airflow control walls 8 is two, but is not particularly limited, and may be one, or three or more.

In the basic example, the airflow control wall 8 is arranged with reference to the second region 412, which is the opposing wall 405 facing the outer surface of the holding block 404 that holds the optical element 401. However, if the airflow control wall 8 controls the airflow so as to reduce the variation in smoke inflow into the smoke detection chamber 4 in the circumferential direction A3 of the smoke detection chamber 4, the airflow control wall 8 may be arranged with the second region 412 as a reference. It doesn't have to be done.

In the basic example, the airflow control wall 8 is formed as part of the upper cover 52 . However, at least a portion of the airflow control wall 8 may be separate from the upper cover 52. For example, the first portion 81 of the airflow control wall 8 may be formed integrally with the flow path forming member 7. Further, for example, the second portion 82 of the airflow control wall 8 may be fixed to the base 2 with an adhesive or the like.

In the basic example, it is assumed that the second region 412 is the opposing wall 405 that faces the outer surface of the holding block 404 that holds the optical element 401. However, the second region 412 may be an opposing wall of the cover 4A that faces the outer surface of the holding block 406 (see FIG. 6) that holds the light receiving element 402.

In the basic example, the smoke detection chamber 4 is mounted on the first surface 21 (upper surface) of the base 2. However, the smoke detection chamber 4 may be mounted on the second surface 22 (lower surface) of the base 2.

In the basic example, the base 2 on which the smoke detection chamber 4 is mounted is a circuit board on which the control section 9 and the like are also mounted. However, the base 2 may be provided separately from the circuit board on which the control section 9 and the like are mounted. However, the basic example can reduce the number of parts.

In the basic example, the mark M1 indicates the orientation related to the notch 73. However, the mark M1 is not limited to the direction related to the notch 73, as long as it indicates the direction related to the specific area in the circumferential direction A4 of the sensor 1.

The mark M1 may be realized by light emitted from a light source such as an LED. In this case, the display unit 10, which is an operating light, may also serve as the mark M1.

(Embodiment 2)
(1) Overview In this embodiment, the airflow is gas containing smoke or steam, and differs from Embodiment 1 in that it includes an inclined portion 202 and an airflow control portion 201. Hereinafter, the differences from the first embodiment will be mainly explained. Components similar to those in Embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. Furthermore, each of the figures described in the following embodiments is a schematic diagram, and the ratio of the size and thickness of each component in each figure does not necessarily reflect the actual size ratio. Not exclusively.

As shown in FIG. 12, the sensor 1D according to this embodiment includes a smoke detection chamber 4, an opening 510, and a dividing portion Z1. The dividing portion Z1 includes an inclined portion 202.

The smoke detection chamber 4 has an inlet 40 through which smoke flows. The opening 510 communicates the external space SP2 with the space SP1 around the smoke detection chamber 4. The inclined portion 202 is arranged in the space SP1 around the smoke detection chamber 4, and divides the gas flow path 6 in the space SP1 around the smoke detection chamber 4. The inclined portion 202 has a first inflow amount of smoke flowing into the gas flow path 6 from the opening 510 and a second inflow amount of steam flowing into the gas flow path 6 from the opening 510. The gas flow path 6 is arranged such that the first ratio of the amount of smoke reaching the inlet 40 to the inflow amount is higher than the second ratio of the amount of steam reaching the inlet 40 to the second inflow amount. To divide.

The inclined portion 202 (divided portion Z1) is formed over the entire circumference of the smoke detection chamber 4, as shown in FIG. Further, as shown in FIGS. 13 and 14, the base 2 is formed into a substantially circular shape as a whole. In this embodiment, one or more (six in FIG. 13) heat detection elements 30 of the heat detection unit 3 are arranged on the outer peripheral portion 23 of the base 2. Furthermore, the base 2 has six tongues 26 each having a heat sensing element 30. Each tongue portion 26 is a portion where a corresponding one of the six heat sensing elements 30 is mounted. The six tongue parts 26 are arranged at equal intervals along the circumferential direction so as to divide the outer peripheral part 23 of the base 2 into approximately six equal parts. Each heat sensing element 30 is mounted near the tip on the upper surface of the corresponding tongue portion 26 . The tongue portion 26 has a through hole 260 having a rectangular opening in a region inside the heat sensing element 30 . By providing the through holes 260 near each heat detection element 30, the area occupied by the base 2 around the heat detection element 30 can be reduced. As a result, the heat in the heat detection element 30 is transmitted through the base 2 and becomes lower, or the heat generated by other circuit components mounted on the main body 20 affects the heat detection element 30. Possibility can be reduced. That is, the through holes 260 improve thermal insulation.

The sensor 1D includes an airflow control section 201 vertically above the outer periphery of the opening 510. The outer peripheral surface 54 of the cylindrical body 51A includes a first peripheral surface 208 on the upper side and a second peripheral surface 204 on the lower side, the first peripheral surface 208 is along the vertical direction A2, and the second peripheral surface 204 is along the vertical direction A2. , is inclined inward from the first circumferential surface 208 so as to form a taper angle θv. The second circumferential surface 204 of this cylindrical body 51A corresponds to the airflow control section 201. The airflow control unit 201 sets the angle between the first circumferential surface 208 and the second circumferential surface 204 of the cylindrical body 51A of the upper cover 53 of the sensor 1D as the taper angle θv of the airflow control unit 201, and uses the taper angle θv to The airflow flowing into the opening 510 from the space SP2 is controlled. Here, "controlling airflow" corresponds to controlling the flow of air so that smoke can easily flow in and steam can hardly flow in. Specifically, smoke can This corresponds to making it easier for steam to flow into the opening 510 while making it difficult for steam to flow into the opening 510 by utilizing the magnitude of inertial force. Furthermore, the airflow control unit 201 controls the total amount of airflow flowing into the opening 510. Regarding the airflow flowing into the opening 510, the airflow control unit 201 determines that smoke easily flows into the opening 510 because it has a large diffusion force and a small inertial force, and steam has a small diffusion force and a large inertial force. This makes it difficult for the liquid to flow into the opening 510. As a result, the airflow control section 201 is controlled so that smoke can easily flow in through the opening 510.

As described above, in this embodiment, since the sensor 1D includes the airflow control section 201, the airflow can be caused to flow into the opening 510 so that smoke can easily flow into the sensor 1D. Therefore, the sensor 1D has the advantage of being able to improve smoke inflow into the smoke detection chamber 4.

(2) Details (2.1) Overall configuration The overall configuration of the sensor 1D according to this embodiment will be described in detail below. The detector 1D is a composite fire detector that detects smoke and heat, as in the first embodiment.

The sensor 1D includes a smoke detection chamber 4 (smoke detection section) and an inclined section 202 of the dividing section Z1. The sensor 1D further includes a base 2 and a housing 5. The sensor 1D further includes a heat detection section 3, a control section 9, and a display section 10. The sensor 1D further includes a disk-shaped mounting base that is fixed to the construction surface 100 by screws or the like. The sensor 1D can be installed on the construction surface 100 by having a mounting portion provided on the upper surface side of the casing 5 removably attached to the mounting base.

The sensor 1D further includes a communication unit 11 that transmits a signal to an external alarm device or the like to notify the occurrence of a fire when a fire is detected, and receives a signal from the alarm device or the like.

The sensor 1D may be powered by a commercial power supply or may be powered by a battery provided inside the housing 5.

The configurations of the above-mentioned parts are generally the same as those explained in "(2.2) Housing" to "(2.6) Control unit" in Embodiment 1, so detailed explanations in this embodiment will be omitted. do.

(2.2) Inclined portion The inclined portion 202 (divided portion Z1) in this embodiment forms a flow path from the opening 510 to the inlet 40 of the smoke detection chamber 4. Between the second space SP4 and the third space SP5, the sensor 1D has a sloped part 202 (divided part Z1) having a sloped surface 203 that slopes vertically upward as it approaches the smoke detection chamber 4. It is equipped with The inclined portion 202 (divided portion Z1) is made of synthetic resin, for example, flame-retardant ABS resin. As shown in FIG. 14, the inclined portion 202 (divided portion Z1) has a substantially ring shape as a whole and has an inner circumferential surface 75A having a cylindrical shape. The inclined portion 202 (divided portion Z1) has an inclined surface 203 that becomes higher in the vertical direction A2 and becomes a concave surface as it goes toward the inner peripheral surface 75A in the radial direction of the sensor 1D. Further, the inclined portion 202 (divided portion Z1) is formed in an annular shape. Further, the inclined portion 202 (divided portion Z1) has an upper surface 207 having a constant height in the horizontal direction. The upper surface 207 is formed in an annular shape with a hole in the center so as to coincide with the inner circumferential surface 75A. That is, the inclined portion 202 (divided portion Z1) is formed over the entire circumference of the smoke detection chamber 4. However, the inclined portion 202 may be formed into a substantially C-shape by cutting out a portion in the circumferential direction.

As shown in FIG. 12, the cross-sectional shape of the inclined portion 202 (divided portion Z1) is such that the horizontal plane perpendicular to the vertical direction A2 of the sensor 1D and the inclined surface 203 form a taper angle θr. The length of the horizontal surface of the inclined surface 203 is a length b2, and the length of the upper surface 207 whose height is constant is a length b3. That is, the length of the inclined portion 202 in the horizontal direction is the sum of the length b2 and the length b3.

Specifically, the inclined part 202 (divided part Z1) divides the smoke detection chamber 4 into a space through which smoke predominantly passes and flows into the smoke detection chamber 4, and a space through which steam predominantly passes and does not flow into the smoke detection chamber 4. The surrounding space SP1 is separated.

The inclined portion 202 (divided portion Z1) is inclined vertically upward as it approaches the smoke detection chamber 4 between the second space SP4 and the third space SP5. The inclined portion 202 (divided portion Z1), together with the upper cover 53 in which the upper cover 52 in Embodiment 1 is partially deformed, connects the gas flow path 6 to the first space SP3, the second space SP4, and the third space SP5. To divide. That is, the inclined part 202 (divided part Z1) divides the space SP1 around the smoke detection chamber 4 into a first space SP3, a second space SP4, and a third space SP5, and The smoke detection chamber 4 is configured to allow the smoke to flow into the smoke detection chamber 4 from the inlet 40. Specifically, the inclined portion 202 (divided portion Z1), the first space SP3, the second space SP4, and the third space SP5 are surrounded by the upper cover 53, the base 2, and the smoke detection chamber 4. In the cross-sectional view shown in FIG. 12, the first space SP3 is a space around the opening 510, and is a space outside the inner surface 209 of the cylindrical body 51A (see FIG. 12). The second space SP4 is a space from the inner surface 209 to the upper corner P0 of the inclined portion 202 (see the enlarged view in FIG. 12). The third space SP5 is a space from the upper corner P0 of the inclined portion 202 to the inlet 40 of the smoke detection chamber 4. The above regulations regarding the ranges of the first space SP3, the second space SP4, and the third space SP5 are merely examples, and are not intended to strictly define the ranges of these spaces. The first space SP3, the second space SP4, and the third space SP5 form an annular space with the smoke detection chamber 4 at the center.

As shown in FIG. 12, the opening 510 and the first space SP3, the first space SP3 and the second space SP4, and the second space SP4 and the third space SP5 are connected to each other from the opening 510 toward the smoke detection chamber 4. They are adjacent to each other in the direction. Here, regarding the first inflow amount of smoke and the second inflow amount of steam, in the third space SP5, the first ratio of smoke is higher than the second ratio of steam. Note that this is not the case in the first space SP3 and the second space SP4.

Regarding the volumes of the first space SP3, the second space SP4, and the third space SP5, the volume of the second space SP4 is larger than each of the volumes of the first space SP3 and the third space SP5. Here, the "volume" of each of the first space SP3, the second space SP4, and the third space SP5 corresponds to the volume of the entire ring-shaped space formed by each of these spaces.

In addition, as shown in FIG. 12, the first space SP3, the second space SP4, and the third space SP5 are viewed in a cross section along one direction and the vertical direction A2 from the opening 510 of the sensor 1D toward the smoke detection chamber 4. , the cross-sectional area of the second space SP4 is larger than each of the cross-sectional areas of the first space SP3 and the third space SP5. Here, the one direction from the opening 510 toward the smoke detection chamber 4 corresponds to the direction along the radial direction of the sensor 1D when facing toward the smoke detection chamber 4 from the opening 510 of the sensor 1D. .

Furthermore, as shown in FIG. 12, the first space SP3, the second space SP4, and the third space SP5 are viewed in a cross section along one direction and the vertical direction A2 from the opening 510 of the sensor 1D toward the smoke detection chamber 4. , in the vertical direction A2 of the sensor 1D, the length of the second space SP4 is longer than the length of each of the first space SP3 and the third space SP5. Here, the length of each space in the vertical direction A2 is defined as the length in the horizontal direction as shown in FIG. On the other hand, the length in the vertical direction A2 is the longest. In FIG. 12, the lengths of the first space SP3, the second space SP4, and the third space SP5 in the vertical direction A2 are indicated as SM1, SM2, and SM3, respectively.

Similarly, as shown in FIG. 12, a cross section of the first space SP3, the second space SP4, and the third space SP5 is taken along one direction and the vertical direction A2 from the opening 510 of the sensor 1D toward the smoke detection chamber 4. Here, in one direction from the opening 510 of the sensor 1D toward the smoke detection chamber 4, the length of the second space SP4 is longer than the length of each of the first space SP3 and the third space SP5. Here, the horizontal length of each space is defined as the length of the sensor 1D at the starting point and end point of each space in a cross section along one direction and the vertical direction A2 from the opening 510 of the sensor 1D toward the smoke detection chamber 4. This corresponds to the length along one direction from the opening 510 toward the smoke detection chamber 4. As shown in FIG. 12, the horizontal lengths of the first space SP3, the second space SP4, and the third space SP5 are indicated as SL1, SL2, and SL3, respectively. As shown in FIG. 12, the horizontal length of each space corresponds to the longest length in the horizontal direction.

In other words, the second space SP4 is larger than the first space SP3 and the third space SP5 in terms of volume, radial cross-sectional area, vertical length A2 in the radial cross-section, and radial length in the radial cross-section. are larger than their respective values.

Further, between the second space SP4 and the third space SP5, the sensor 1D has an inclined part 202 (divided part Z1). The horizontal plane perpendicular to the vertical direction of the sensor 1D and the inclined surface 203 of the inclined part 202 (divided part Z1) form a taper angle θr. As shown in FIG. 12, in the cross section of the inclined surface 203, the inclined surface 203 is inclined vertically upwardly toward the interior in one direction from the opening 510 toward the smoke detection chamber 4. The inclined surface 203 has a curved shape that is concave downward in the vertical direction A2. Here, the taper angle θr is defined as the imaginary line b4 connecting the upper angle P0 and the lower angle Q0 of the inclined surface 203, and the first surface 21 (upper surface) of the base 2, as shown in the enlarged view in FIG. , is defined as the taper angle θr.

Next, the influence of the taper angle θr of the inclined portion 202 (divided portion Z1) on the smoke inflow time and steam reduction rate regarding the response of the sensor 1D to smoke will be explained. Here, the smoke inflow time related to the response of the sensor 1D to smoke means the time it takes for smoke flowing in from the opening 510 to reach the smoke detection chamber 4 via the surrounding space SP1, and the response to smoke It is a time that is an indicator of sexuality. On the other hand, the steam reduction rate indicates how much the amount of steam can be reduced with respect to the taper angle that is the reference when changing the taper angle θr with a certain taper angle as a reference. In the graph of the steam reduction rate, as the value becomes smaller, it represents that the amount of steam can be reduced compared to the amount of steam entering the smoke detection chamber 4 in the case of the standard taper angle. In the graph shown in FIG. 15A, as an example, the ratio is expressed with the taper angle θr being 60° as the reference taper angle. In other words, the ratio is displayed with the case of a taper angle of 60 degrees as "1". As shown in the graph of FIG. 15A, the graph X50 indicating the smoke inflow time does not change significantly in the range of the taper angle θr from 35° to 90°. Therefore, even if the taper angle θr of the inclined portion 202 (divided portion Z1) is changed within the range of 35° to 90°, the responsiveness to fire hardly changes. On the other hand, in graph X60 showing the steam reduction rate, as the taper angle θr increases, it decreases greatly. In particular, as the taper angle θr approaches 90° from 60°, steam can be significantly reduced. From this, by setting the taper angle θr to an appropriate value, it is possible to reduce the amount of steam in the case of inflow of steam, while also reducing the amount of smoke inflow without impairing the responsiveness to smoke. It is possible to keep time. For example, the taper angle θr is preferably set within a range of 60° to 90°, more preferably 70° to 80°. Note that the taper angle θr in FIG. 12 is 70° as an example. That is, by increasing the taper angle θr, when smoke flows in, the responsiveness of the sensor 1D to smoke is hardly impaired, and when steam flows in, the ratio of steam can be reduced. Therefore, it can be said that the inclined part 202 (divided part Z1) can suppress false alarms when steam flows in while maintaining almost all responses to smoke caused by a fire.

(2.3) Airflow Control Unit The sensor 1D includes an airflow control unit 201 that controls the amount of airflow flowing into the opening 510 of the sensor 1D from the external space SP2. The airflow control unit 201 is arranged vertically above the outer periphery of the opening 510 and controls gas to flow into the opening 510 . The airflow control unit 201 controls the main airflow containing smoke or steam in the external space SP2 into a first airflow that does not flow into the gas flow path 6 from the opening 510 and a second airflow that flows into the gas flow path 6 from the opening 510. Separate into two parts. The airflow control unit 201 is configured such that the ratio of the amount of smoke in the second airflow to the amount of smoke in the first airflow when the main airflow includes smoke is the same as the ratio of the amount of smoke in the second airflow to the amount of smoke in the first airflow when the main airflow includes steam. The main airflow is controlled so that the ratio of the amount of steam in the two airflows is higher than that of the two airflows. Specifically, as shown in FIG. 12, in the upper cover 53 of the sensor 1D, the airflow control unit 201 controls the first circumference of the outer circumferential surface 54 of a flat cylindrical body 51A with open upper and lower ends. It includes a second circumferential surface 204 that is derived from surface 208 . In the outer circumferential surface 54 of the cylindrical body 51A, the angle formed by the first circumferential surface 208 and the second circumferential surface 204 is defined as a taper angle θv. As the taper angle θv increases, the airflow of smoke or steam becomes easier to flow into the opening 510 of the sensor 1D, and the amount of airflow flowing into the opening 510 increases. On the other hand, as the taper angle θv decreases, the airflow of smoke or steam becomes difficult to flow into the opening 510 of the sensor 1D, and the amount of airflow flowing into the opening 510 decreases. That is, by controlling the taper angle θv, the airflow of smoke or steam flowing into the sensor 1D can be controlled.

FIG. 15B shows the relationship between the taper angle θv, the smoke inflow time, and the steam reduction rate described above. In the graph shown in FIG. 15B, a graph X10 showing the smoke inflow time and a graph X20 showing the steam reduction rate are displayed as ratios based on the case where the taper angle θv is 30°. As for the steam reduction rate, the lower the value, the more the amount of steam can be reduced with respect to the standard taper angle of 30°. When the taper angle θv changes from 0° to 30°, the graph X10 showing the rate of change in smoke inflow time hardly changes. On the other hand, the rate of change of graph X20 showing the steam reduction rate is such that as the taper angle θv approaches 0°, the steam reduction rate increases. That is, by increasing the taper angle θv, in the case of steam, the amount of steam can be reduced relative to the reference taper angle (30° in FIG. 15B) without substantially impairing the responsiveness of the sensor 1D to smoke. By using the taper angle θv of the airflow control unit 201, when smoke from a fire flows in from the opening 510, the proportion of smoke flowing in from the opening 510 is increased, and steam flows in from the opening 510. In this case, it can be said that the steam ratio has been reduced. Note that the taper angle θv is preferably in the range of 0° to 30°, more preferably in the range of 0° to 15°, for example. Note that the taper angle θv in FIG. 12 is 11° as an example.

As shown in FIG. 12, if the thickness of the cylindrical body 51A of the lower cover 51 in the radial direction of the portion of the airflow control unit 201 that does not have the taper angle θv is the thickness a1, then the thickness a1 is the response of the sensor 1D to smoke. It has the effect of suppressing the inflow of steam when it comes in, while maintaining the smoke responsiveness that is characteristic. FIG. 15C shows the relationship between the thickness a1 and the above-mentioned smoke inflow time and steam reduction rate. In the graph shown in FIG. 15C, a graph X30 indicating the smoke inflow time and a graph X40 indicating the steam reduction rate are displayed as a ratio with respect to the case where the thickness a1 is 9 mm. When the thickness a1 is changed from 9 mm to 1 mm, the graph X30 showing the smoke inflow time hardly changes with respect to the standard thickness of 9 mm, whereas the graph X40 showing the steam reduction rate is based on the thickness a1. As the thickness decreases from 9 mm, the amount of steam decreases. That is, by reducing the thickness a1, the responsiveness of the sensor 1D to smoke is hardly impaired, and when steam flows in, the amount of steam can be reduced. That is, the thickness a1 of the airflow control section 201 can increase the smoke ratio when smoke from a fire flows in from the opening 510, and decrease the steam ratio when steam flows from the opening 510. It can be said that it is. This is because the particle size of steam is, for example, about 10 μm, whereas the particle size of smoke is, for example, about 0.1 μm. Furthermore, since the mass of smoke particles is smaller than the mass of steam particles, the inertial force of smoke particles is smaller than the inertial force of steam particles. Even if the thickness a1 becomes thinner, smoke has diffusivity and is hardly affected by the thickness a1. On the other hand, when the thickness a1 of the inner surface 209 of the cylindrical body 51A becomes thinner in the direction of the external space SP2, the second space SP4 becomes wider, so even steam with a large inertial force tends to swirl. Become. On the other hand, when the thickness a1 of the inner surface 209 of the cylindrical body 51A increases in the direction of the smoke detection chamber 4, the second space SP4 that changes the gas flow path 6 becomes narrower, making it difficult to form a vortex, and smoke detection The amount of steam reaching chamber 4 increases.

(2.4) Inclined portion (divided portion Z1) and airflow control portion As described above, the sensor 1D includes the inclined portion 202 (divided portion Z1) and the airflow control portion 201. As shown in FIG. 12, the thickness in one direction from the opening 510 of the airflow control unit 201 toward the smoke detection chamber is the thickness a1, the vertical length of the airflow control unit 201 is the length a2, and the outer peripheral surface of the cylindrical body 51A. The angle between the first circumferential surface 208 and the second circumferential surface 204 of 54 is defined as a taper angle θv. As an example, the sensor 1D of this embodiment has a thickness a1 of 5 mm, a length a2 of 10.64 mm, and a taper angle θv of 11°. Furthermore, as shown in FIG. 12, in the inclined surface 203 of the inclined section 202 (divided section Z1), the length of the distance from the airflow control section 201 to the inclined section 202 (divided section Z1) is b1, and the diameter of the inclined surface 203 is Let b2 be the length in the direction, and b3 be the length where the height of the inclined portion 202 (divided portion Z1) is constant. As an example, the sensor 1D of this embodiment has a length b1 of 13.65 mm, a length b2 of 4.29 mm, and a length b3 of 6.11 mm. Note that these numerical values are just examples, and are not intended to be limited to these numerical values.

(3) Operation <Operation example 1> Case where smoke flows in Here, the case where smoke flows in will be explained. As described above, the airflow control unit 201 provided vertically above the outer periphery of the opening 510 separates a portion of smoke from the airflow containing smoke. The airflow control section 201 configured by the taper angle θv and the thickness a1 described above allows smoke to easily enter the space SP1 having the slope portion 202 (divided portion Z1) from the opening portion 510. In other words, smoke is less affected by the airflow control section 201 and easily flows into the sensor 1D through the opening 510. Therefore, in the airflow containing smoke, the proportion of smoke in the airflow flowing into the opening 510 via the airflow control unit 201 increases compared to the airflow in the external space SP2.

Specifically, as shown in FIG. 12, the airflow control unit 201 forms a smoke branch 65 that flows into the opening 510 from the smoke airflow 63 in the external space SP2. Here, the ratio between the smoke airflow 63 and the smoke branch flow 65 is, for example, 75% and 25%. This means that the airflow control unit 201 prevents most of the gas containing smoke from flowing in through the opening 510. Note that this value is just an example, and is not intended to be fixed at this value.

Next, the airflow containing smoke that has flowed into the opening 510 of the sensor 1D reaches the first space SP3 of the spaces SP1. When the airflow further flows into the sensor 1D, it reaches the second space SP4 from the first space SP3. As mentioned above, in the second space SP4, the volume and the cross-sectional area in the vertical direction perpendicular to one direction from the opening 510 to the smoke detection chamber 4 are larger than the respective values of the first space SP3 and the third space SP5. It's getting bigger. In addition, in the vertical length in the vertical cross section perpendicular to one direction from the opening 510 to the smoke detection chamber 4, and the length in one direction from the opening 510 to the smoke detection chamber 4, the first space SP3 and the values of the third space SP5. Note that although it is preferable that all of these conditions be met, it is not essential that all of these conditions be met.

Further, an inclined portion 202 (divided portion Z1) having an inclined surface 203 with a taper angle θr exists between the second space SP4 and the third space SP5.

Therefore, as shown in FIG. 12, the airflow flowing into the second space SP4 flows in one direction, from vertically downward to vertically upward, from the opening 510 of the sensor 1D to the smoke detection chamber 4, for example. It begins to flow in a rotating manner from the inside to the outside, and from vertically upward to vertically downward. In this case, the smoke has a small smoke particle diameter, so the diffusion force is large and the inertial force is small. Therefore, part of the smoke can flow into the third space SP5 with respect to the second space SP4.

Specifically, as shown in FIG. 12, the sensor 1D includes an inclined portion 202, and further includes a cross section along one direction and the vertical direction A2 from the opening 510 of the second space SP4 toward the smoke detection chamber 4. The cross-sectional area of the first space SP3 and the third space SP5 is larger than the cross-sectional area of the cross section along the one direction toward the smoke detection chamber 4 from the opening 510 and the vertical direction A2, so that no smoke is generated in the second space SP4. A vortex 67B is formed. Further, a separated smoke flow 67A is formed in a form that is formed with the smoke vortex flow 67B. The separated smoke flow 67A flows from the second space SP4 to the third space SP5, and then flows into the smoke detection chamber 4 from the inlet 40.

As mentioned above, smoke particles have a large diffusion force and a small inertial force. Therefore, the smoke that has flowed into the second space SP4 forms a swirling smoke flow 67B due to the inclined portion 202, while a separated smoke flow 67A heading from the second space SP4 toward the third space SP5 is formed. In other words, it is arranged around the smoke detection chamber 4 to form a space through which smoke predominantly passes through the gas flow path 6 and flows into the smoke detection chamber. Compared to the ratio of smoke in the separated smoke flow 65 that flows in from the opening 510, the ratio of smoke in the separated flow 67A of smoke heading from the second space SP4 to the third space SP5 is higher in the separated flow 67A. is getting bigger. That is, the inclined portion 202 (divided portion Z1) forms a space (third space SP5 in this embodiment) through which smoke predominantly passes and flows into the smoke detection chamber 4.

Therefore, the inclined portion 202 (divided portion Z1) has a taper angle θr, and further utilizes the difference in size of the first space SP3, the second space SP4, and the third space SP5 to reduce smoke. A vortex flow 67B and a separated smoke flow 67A can be formed. The smoke airflow that has flowed into the third space SP5 has a higher proportion of smoke than the airflow in the second space SP4, and has reached the smoke detection chamber 4 from the third space SP5 via the inlet 40. Due to the airflow, the sensor 1D can detect a fire and issue an alarm.

<Operation example 2> Case in which steam flows in Next, a case in which steam flows in will be described. As described above, a portion of the steam-containing airflow is separated by the airflow control section 201 provided vertically above the outer periphery of the opening 510. The airflow control unit 201 configured by the taper angle θv and the thickness a1 described above makes it difficult for steam to enter the space SP1 from the opening 510. In other words, steam is affected by the airflow control unit 201 and is difficult to flow into the sensor 1D from the opening 510. Therefore, in the airflow containing steam, the ratio of steam in the airflow flowing into the opening 510 via the airflow control unit 201 is lower than that in the airflow in the external space SP2. This is because the steam particle diameter is large, so the inertial force is large and the diffusion force is small. Therefore, most of the steam cannot flow into the sensor 1D through the opening 510 due to the effect of the airflow control unit 201 and the above-mentioned properties of the steam itself.

Specifically, as shown in FIG. 12, the airflow control unit 201 forms a steam branch 66 that flows into the opening 510 from the steam airflow 64 in the external space SP2. Here, the ratio of the steam airflow 64 and the steam division 66 is, for example, 75% and 25%. That is, this means that the airflow control unit 201 prevents most of the gas containing steam from flowing in through the opening 510. Note that this value is just an example, and is not intended to be fixed at this value.

Next, the airflow containing steam that has flowed into the opening 510 of the sensor 1D reaches the first space SP3 of the spaces SP1. When the airflow further flows into the sensor 1D, it reaches the second space SP4 from the first space SP3. In the second space SP4, as described above, the volume, the cross-sectional area in the vertical direction perpendicular to one direction from the opening 510 to the smoke detection chamber 4, and the vertical cross-sectional area perpendicular to one direction from the opening 510 to the smoke detection chamber 4. The length in the vertical direction in the cross section of the direction and the length in one direction from the opening 510 toward the smoke detection chamber 4 are larger than the respective values of the first space SP3 and the third space SP5. Further, an inclined portion 202 (divided portion Z1) having an inclined surface 203 having a taper angle θr is provided between the second space SP4 and the third space SP5. Therefore, as shown in FIG. 12, the airflow flowing into the second space SP4 including the inclined part 202 (divided part Z1) moves from the vertically downward direction to the vertically upwardly direction in the second space SP4, toward the opening of the sensor 1D. The smoke flows in one direction from 510 toward the smoke detection chamber 4, from inside to outside, and from vertically upward to vertically downward in a rotating manner. In this case, the steam, which has a larger particle diameter than the smoke and is heavier than the smoke, has a large inertial force and a low diffusion force relative to the smoke, so it flows in a swirling manner in the second space SP4. do.

Specifically, as shown in FIG. 12, the sensor 1D includes an inclined portion 202, and further includes a cross section along one direction and the vertical direction A2 from the opening 510 of the second space SP4 toward the smoke detection chamber 4. The cross-sectional area of the first space SP3 and the third space SP5 is larger than the cross-sectional area of the cross section along the one direction toward the smoke detection chamber 4 from the opening 510 of the third space SP5 and the vertical direction A2. In this case, a steam vortex 68B is formed. Further, a separated steam flow 68A is formed to be separated from the steam vortex flow 68B. The separated steam flow 68A flows from the second space SP4 to the third space SP5, and then flows into the smoke detection chamber 4 from the inlet 40.

As described above, steam particles have a small diffusion force and a large inertial force relative to smoke particles, so the steam vortex 68B becomes the mainstream, and the steam separate flow 68A heads from the second space SP4 to the third space SP5. becomes smaller. Compared to the ratio of steam in the steam separation flow 66 that flows in from the opening 510, the ratio of steam in the steam separation flow 68A heading from the second space SP4 to the third space SP5 is such that the ratio of steam in the steam separation flow 66 is It's getting bigger. That is, the inclined portion 202 (divided portion Z1) forms a space (second space SP4 in this embodiment) through which steam predominantly passes and does not flow into the smoke detection chamber 4.

Therefore, the inclined portion 202 (divided portion Z1) has a taper angle θr, and further utilizes the difference in size of the first space SP3, the second space SP4, and the third space SP5 to It is possible to form a space in which the smoke does not flow into the smoke detection chamber 4. The steam airflow flowing into the third space SP5 has a lower steam ratio than the airflow in the second space SP4, and reaches the smoke detection chamber 4 from the third space SP5 via the inlet 40. Due to the airflow, the sensor 1D can detect a fire and suppress false alarms.

(4) Advantages The sensor 1D includes a smoke detection chamber 4, an opening 510, and an inclined portion 202 (divided portion Z1). The smoke detection chamber 4 has an inlet 40 through which smoke flows. The opening 510 communicates the external space SP2 with the space SP1 around the smoke detection chamber 4. The inclined portion 202 (dividing portion Z1) is arranged in the space SP1 around the smoke detection chamber 4 and divides the gas flow path 6. The dividing part Z1 has a first inflow amount of smoke flowing into the gas flow path 6 from the opening 510 and a second inflow amount of steam flowing into the gas flow path 6 from the opening 510. The gas flow path 6 is arranged such that the first ratio of the amount of smoke reaching the inlet 40 to the inflow amount is higher than the second ratio of the amount of steam reaching the inlet 40 to the second inflow amount. To divide.

According to this configuration, by dividing the gas flow path 6, it is possible to suppress false alarms from the sensor 1D.

The inclined portion 202 (divided portion Z1) forms a first space SP3, a second space SP4, and a third space SP5, which are gas flow paths 6. The external space SP2 and the first space SP3, the first space SP3 and the second space SP4, and the second space SP4 and the third space SP5 head toward the smoke detection chamber 4 from the opening 510 of the inclined part 202 (divided part Z1). They are adjacent to each other in one direction. In the cross section along one direction and the vertical direction from the opening 510 of the sensor 1D toward the smoke detection chamber 4, the cross-sectional area of the second space SP4 is larger than each of the cross-sectional areas of the first space SP3 and the third space SP5. big.

According to this configuration, the inclined part 202 (divided part Z1) is provided, and the cross-sectional area of the second space SP4 is larger than each of the cross-sectional areas of the first space SP3 and the third space SP5. The gas that has flowed into the second space SP4 forms a vortex from the vertically lower side of the second space SP4 to the vertically upper side, from the inside of the second space SP4 to the outside, and further from the vertically upper side of the second space SP4 to the vertically lower side. It flows as if rolling. In a gas containing steam, the steam flows in a swirling manner due to inertial force. On the other hand, smoke can flow from the second space SP4 to the third space SP5 according to the diffusion force, and the smoke and steam can be separated by the relative sizes of the inclined part 202 (divided part Z1) and the second space SP4. Can be separated. Therefore, false alarms due to steam in the sensor 1D can be suppressed.

The inclined part 202 (divided part Z1) is an inclined surface between the second space SP4 and the third space SP5 that is inclined vertically upward as it advances in one direction from the opening 510 toward the smoke detection chamber 4. 203 is provided.

According to this configuration, the inclined portion 202 (divided portion Z1) causes the gas containing smoke or steam to flow in a swirling manner in the second space SP4. As the gas containing smoke or steam flows in a swirling manner, the inclined portion 202 utilizes the diffusion force of the smoke and the inertial force of the steam to prevent the smoke from flowing into the gas flow path 6 from the opening 510. and the second inflow amount of steam flowing into the gas flow path 6 from the opening 510, the first ratio of the amount of smoke reaching the inlet 40 to the first inflow amount is , the gas flow path 6 is divided so that the amount of steam reaching the inlet 40 is higher than the second ratio with respect to the second amount of inflow. Therefore, false alarms due to steam in the sensor 1D can be suppressed.

The sensor 1D includes an airflow control unit 201 that is arranged vertically above the outer periphery of the opening 510 and controls gas to flow into the opening 510. The airflow control unit 201 divides the main airflow containing smoke or steam in the external space SP2 into a first airflow that does not flow into the gas flow path 6 from the opening 510 and a second airflow that flows into the gas flow path 6 from the opening 510. Separate into airflow. The airflow control unit 201 is configured such that the ratio of the amount of smoke in the second airflow to the amount of smoke in the first airflow when the main airflow includes smoke is the same as the ratio of the amount of smoke in the second airflow to the amount of smoke in the first airflow when the main airflow includes steam. The airflow is controlled so that the ratio of the amount of steam in the two airflows is higher than that of the two airflows.

According to this configuration, the airflow control unit 201 controls the main airflow containing smoke or steam in the external space SP2 by utilizing the large diffusion force and small inertial force of smoke while controlling the total amount of gas. The first airflow does not flow into the gas flow path 6 from the opening 510, and the second airflow flows into the gas flow path from the opening 510. The airflow control unit 201 is configured such that the ratio of the amount of smoke in the second airflow to the amount of smoke in the first airflow when the main airflow includes smoke is the same as the ratio of the amount of smoke in the second airflow to the amount of smoke in the first airflow when the main airflow includes steam. The airflow is controlled so that the ratio of the amount of steam in the two airflows is higher than that of the two airflows. On the other hand, the airflow control unit 201 can reduce the amount of steam in the second airflow when the main airflow contains steam, by utilizing the fact that the diffusion force of steam is smaller than that of smoke and the inertial force is large.

(5) Modifications The above embodiment is just one of various embodiments of the present disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objective of the present disclosure can be achieved. Modifications of the above embodiment will be listed below. The modified examples described below can be applied in combination as appropriate.

In the second embodiment, the configuration includes both the airflow control section 201 and the inclined section 202 (divided section Z1), but the present invention is not limited to this configuration. It may be a combination of the airflow control section 201 and the airflow control wall 8 of the first embodiment. Further, the airflow control section 201 may not be installed, and the inclined section 202 (divided section Z1) may be installed alone. Furthermore, a combination of the airflow control section 201 and the branch section 71 described in Embodiment 1 may be used.

In the second embodiment, as shown in FIG. 19, the inclined portion 202 (divided portion Z1) has a configuration in which the shape of the vertical cross section is a curved shape having a concave surface, but the configuration is not limited to this. The shape of the vertical cross section may be, for example, a straight line, as shown in FIG. In this case, the inclined surface 203A of the inclined portion 202A has a taper angle θr with respect to the horizontal plane of the sensor 1H.

In the second embodiment, the configuration includes the airflow control section 201 and the inclined section 202 (divided section Z1), but the configuration is not limited to this. As shown in FIG. 16, the airflow control unit 201 may further include a protrusion 205 that restricts the airflow. The sensor 1E shown in FIG. 16 includes the protrusion 205, so that the airflow flowing into the opening 510 can be further restricted. Therefore, steam, which has a large inertial force with respect to smoke and a low diffusion force, becomes more difficult to flow in through the opening 510 than in the second embodiment. Specifically, as shown in FIG. 16, the gas flow path 6 is separated into a flow path 69A, which is the main flow of air containing smoke or steam, and a flow path 69B, which flows into the sensor 1D from the opening 510. do. Therefore, due to the combination of the airflow control unit 201 and the protrusion 205, the smoke-containing gas flowing into the opening 510 has a higher proportion of smoke than the gas in the external space SP2. On the other hand, when gas containing steam flows in, comparing the flow path 69A and the flow path 69B, the flow path 69B can lower the ratio of steam. In the sensor 1E shown in FIG. 16, the vertical cross section of the protrusion 205 has a triangular shape, but is not limited to this shape. The shape of the vertical cross section of the protrusion 205 may be, for example, square, rectangle, trapezoid, or semicircle.

In the second embodiment, a vertical cross section perpendicular to the radial direction of the airflow control unit 201 has a taper angle θv between the first circumferential surface 208 and the second circumferential surface 204 of the outer circumferential surface 54 of the cylindrical body 51A. Although the second circumferential surface 204 in the cross section of the portion 201 is a straight line, the present invention is not limited to this configuration. For example, as shown in FIG. 17, the vertical cross section of the airflow control section 201A may have a tapered section 204A having a curved line. In the sensor 1F shown in FIG. 17, the tapered portion 204A is a curved line. Therefore, steam, which has a large inertial force with respect to smoke and a low diffusion force, becomes more difficult to flow in through the opening 510 than in the second embodiment. Specifically, as shown in FIG. 17, the airflow control unit 201A is divided into a flow path 69C, which is the main airflow of smoke or steam, and a flow path 69D. The airflow control unit 201A determines that the ratio of smoke contained in the flow path 69D flowing into the gas flow path 6 from the opening 510 to the smoke contained in the flow path 69C, which is the main airflow, is the main airflow containing steam. The airflow is restricted so that the ratio of steam contained in a certain flow path 69C to the steam contained in the flow path 69D flowing into the opening 510 is higher than that of the steam contained in the flow path 69D. Therefore, the airflow control unit 201A can suppress malfunction of the sensor 1F due to steam.

In the second embodiment, the configuration includes the airflow control section 201 and the opening 510, but the configuration is not limited to this. As in the sensor 1G shown in FIG. 18, the opening 510A may have a restriction part 206 formed vertically upward from the lower end of the opening 510A. The restriction portion 206 is formed to protrude vertically upward from the lower end of the opening 510A, thereby restricting the airflow flowing in from the opening 510A. Therefore, compared to the second embodiment, steam having a large inertial force and a low diffusion force relative to smoke is more difficult to flow in through the opening 510A. Specifically, in the gas flow path 6 that is separated into a flow path 69E, which is the main gas flow, and a flow path 69F, the restriction portion 206 connects the sensor 1G of the separated 69F. limit the influx of The airflow control unit 201 determines that the ratio of the amount of smoke in the separated flow path 69F to the amount of smoke when smoke is contained in the flow path 69E, which is the main airflow, is such that steam is contained in the flow path 69E, which is the main airflow. The ratio of the amount of steam in the separated flow path 69F to the amount of steam in the case is set higher than the ratio of the amount of steam in the separated flow path 69F. The restricting unit 206 can further reduce the amount of steam, so that the ratio of the amount of steam to the amount of smoke contained in the flow path 69F can be restricted so that the ratio of the amount of smoke is greater. In FIG. 18, the shape of the vertical cross section of the restricting portion 206 is rectangular, but the configuration is not limited to this. The shape of the vertical cross section of the restriction portion 206 may be, for example, square, trapezoid, triangle, or semicircle.

(6) Summary As explained above, the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the first aspect has a smoke detection chamber (4) and an opening ( 510, 510A) and a dividing portion (Z1). The smoke detection chamber (4) has an inlet (40) through which smoke flows. The opening (510, 510A) communicates the external space (SP2) with the space (SP1) around the smoke detection chamber (4). The dividing part (Z1) is arranged in the space (SP1) around the smoke detection chamber (4) and divides the gas flow path (6). The dividing part (Z1) has a first inflow amount of smoke flowing into the gas flow path (6) from the opening (510, 510A) and a first inflow amount of smoke flowing into the gas flow path (6) from the opening (510, 510A). With respect to the second inflow amount of steam flowing in, the first ratio of the amount of smoke reaching the inlet (40) to the first inflow amount is such that the steam reaching the inflow port (40) to the second inflow amount The gas flow path (6) is divided so that the second proportion of the amount is higher than the second proportion. According to the first aspect, the possibility of false detection occurring can be reduced.

In the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the second aspect, in the first aspect, the dividing part (Z1) is connected to the branching part (71, 71A, 71B). ). The branch part (71, 71A, 71B) divides the space (SP1) around the smoke detection chamber (4) into two in a separation direction (A1) including a vertical direction (A2) component, and creates a gas flow path (6 ) is branched (divided) into two, an upper flow path (61) and a lower flow path (62). The branch part (71, 71A, 71B) directs the smoke that has passed through the upper channel (61) of the upper channel (61) and the lower channel (62) from the inlet (40) to the smoke detection chamber ( 4). According to the second aspect, the possibility of false detection occurring can be reduced.

The sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the third aspect has a lower flow path (62) and a smoke detection chamber (4). It further includes a blocking part (72) disposed between the smoke detection chamber (4) and blocking the steam passing through the lower flow path (62) from flowing into the smoke detection chamber (4). According to the third aspect, it becomes more difficult for steam to flow into the smoke detection chamber (4), and the occurrence of false detection can be further suppressed.

Regarding the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the fourth aspect, in the second or third aspect, the branch part (71, 71A, 71B) It is formed over the entire circumference of the detection chamber (4). According to the fourth aspect, no matter which direction steam enters the sensor (1, 1A, 1B, 1C) from 360 degrees, it becomes difficult to flow into the smoke detection chamber (4), resulting in false detection. The occurrence can be further suppressed.

Regarding the sensor (1, 1A, 1B, 1C) according to the fifth aspect, in any one of the second to fourth aspects, the peripheral wall (41) of the smoke detection chamber (4) is connected to the inlet (40). ) and a second region (412) in which no inlet (40) is formed. The branch portion (71, 71A, 71B) has a notch (73) at a position facing the second region (412). According to the fifth aspect, smoke entering the sensor (1, 1A, 1B, 1C) toward the second region (412) may be difficult to flow into the smoke detection chamber (4). It is possible to reduce the

Regarding the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the sixth aspect, in any one of the first to fifth aspects, the dividing part (Z1) is The gas flow path (6) is divided into a first space (SP3), a second space (SP4), and a third space (SP5). The opening (510, 510A) and the first space (SP3), the first space (SP3) and the second space (SP4), and the second space (SP4) and the third space (SP5) are , 510A) to the smoke detection chamber (4). Regarding the first inflow amount of smoke and the second inflow amount of steam, in the third space (SP5), the first ratio of smoke is higher than the second ratio of steam. The volume of the second space (SP4) is larger than the volume of each of the first space (SP3) and the third space (SP5). According to the sixth aspect, the volume of the second space (SP4) becomes larger than the volume of each of the first space (SP3) and the third space (SP5), so that the volume of the second space (SP4) flows into the second space (SP4). Smoke or steam, and gases containing smoke and steam tend to form vortices.

Regarding the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the seventh aspect, in any one of the first to sixth aspects, the dividing part (Z1) is The gas flow path (6) is divided into a first space (SP3), a second space (SP4), and a third space (SP5). The opening (510, 510A) and the first space (SP3), the first space (SP3) and the second space (SP4), and the second space (SP4) and the third space (SP5) are , 510A) to the smoke detection chamber (4). Regarding the first inflow amount of smoke and the second inflow amount of steam, in the third space (SP5), the first ratio of smoke is higher than the second ratio of steam. In the cross section along one direction and the vertical direction (A2) from the opening (510) of the dividing part (Z1) toward the smoke detection chamber (4), the cross-sectional area of the second space (SP4) is equal to the first space (SP3). ) and the cross-sectional area of the third space (SP5). According to the seventh aspect, the cross-sectional area of the second space (SP4) is larger than the cross-sectional area of each of the first space (SP3) and the third space (SP5), so that the second space (SP4) The smoke or steam that has flowed in, and the gas containing the smoke and steam, tend to form vortices.

Regarding the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the eighth aspect, in the sixth or seventh aspect, the smoke detection chamber ( 4) In the cross section along one direction and the vertical direction (A2), the length of the second space in the vertical direction is equal to the length of the first space (SP3) and the third space (SP5) in the vertical direction (A2). longer than each of the s. According to the eighth aspect, the vertical length of the cross-sectional area of the second space (SP4) is longer than the vertical length of the cross-sectional area of each of the first space (SP3) and the third space (SP5). As a result, the smoke or steam that has flowed into the second space (SP4) and the gas containing smoke and steam tend to form a vortex.

Regarding the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the ninth aspect, in any one of the sixth to eighth aspects, the opening (510, 510A) In the cross section along one direction and the vertical direction (A2) toward the smoke detection chamber (4), the length of the second space (SP4) in one direction is the same as that of the first space (SP3) and the third space (SP5). longer than each of the lengths of . According to the ninth aspect, the length in one direction from the opening (510, 510A) of the second space (SP4) toward the smoke detection chamber (4) in the cross-sectional area of the second space (SP4) is the length of the first space. The smoke or steam that has flowed into the second space (SP4) and the gas containing smoke and steam are It becomes easier to form vortices.

Regarding the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the tenth aspect, in any one of the sixth to ninth aspects, the dividing part (Z1) is An inclined surface (203, 203A) that is inclined vertically upward in one direction is provided between the second space (SP4) and the third space (SP5). According to the tenth aspect, the dividing part (Z1) includes the inclined surfaces (203, 203A), so that the smoke or steam flowing into the second space (SP4), and the gas containing the smoke and steam, flow through the vortex. It becomes easier to form.

Regarding the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the eleventh aspect, in any one of the first to tenth aspects, the opening (510, 510A) The device further includes an airflow control unit (201, 201A) that is arranged vertically above the outer periphery of the device and controls gas to flow into the opening (510, 510A). According to the eleventh aspect, the airflow control unit (201, 201A) restricts the gas flow path (6) to reduce the ratio of smoke and steam of the gas flowing into the opening (510, 510A). , the proportion of smoke can be increased compared to the gas before entering.

Regarding the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the twelfth aspect, in the eleventh aspect, the airflow control unit (201, 201A) A main airflow containing smoke or steam from the opening (510, 510A) that does not flow into the gas flow path (6) and a first airflow that does not flow into the gas flow path (6) from the opening (510, 510A). It separates into a second air stream. The airflow control unit (201, 201A) is configured such that the ratio of the amount of smoke in the second airflow to the amount of smoke in the first airflow when the main airflow contains smoke is equal to the ratio of the amount of smoke in the first airflow to the amount of smoke in the first airflow when the main airflow contains steam. The main airflow is controlled so that the ratio of the amount of steam in the second airflow to the amount of steam is higher than the amount of steam in the second airflow. According to the twelfth aspect, the airflow control unit (201, 201A) separates the main airflow into the first airflow and the second airflow, and adjusts the amount of smoke or steam in the second airflow to the amount of smoke or steam in the first airflow. By controlling the main air flow so that the proportion of smoke is higher than the proportion of steam, it is possible to suppress the occurrence of false detection due to steam.

The sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the thirteenth aspect is configured such that in any one of the first to twelfth aspects, the smoke detection chamber (4) is It further includes a base (2, 2A) mounted thereon. According to the twelfth aspect, in the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G) in which the smoke detection chamber (4) is mounted on the base (2, 2A), The possibility of false positives occurring can be reduced.

Regarding the sensor (1, 1A, 1B, 1C) according to the fourteenth aspect, in the thirteenth aspect, the base (2, 2A) is a circuit board. According to the fourteenth aspect, the number of parts can be reduced compared to, for example, a case where the base (2, 2A) is provided separately from the circuit board.

The sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the 15th aspect is the outer peripheral part (23 ) The apparatus further includes one or more heat sensing elements (30) arranged in the heat sensing element (30). According to the fifteenth aspect, it is possible to reduce the possibility of false detection occurring in the sensors (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) that further have a heat detection function.

Regarding the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the 16th aspect, in the 15th aspect, the outer peripheral part (23) is arranged with the heat sensing element (30). It has a recess (24) recessed inwardly in the peripheral area. According to the sixteenth aspect, it is possible to improve the heat flow properties of the heat sensing element (30).

In any one of the thirteenth to sixteenth aspects, the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the seventeenth aspect includes a base (2, 2A) The device further includes a cylindrical portion (511) arranged to cover the lower surface (second surface 22) of the device. The base (2, 2A) has a protruding edge (25) that protrudes outward from the cylindrical portion (511). According to the seventeenth aspect, the possibility that steam passes through the upper channel (61) can be reduced by the protruding edge (25).

The sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the 18th aspect further includes a lower cover (51) in any one of the 13th to 17th aspects. Be prepared. The lower cover (51) has an opening (510) that communicates the external space (SP2) with the space (SP1) around the smoke detection chamber (4), and has an opening (510) on the underside of the base (2, 2A). Placed. The outer peripheral portion (23) of the base (2, 2A) does not protrude into the external space (SP2) from the opening (510) when the lower cover (51) is viewed from the front. According to the 18th aspect, the outer peripheral part (23) of the base (2, 2A) connects the sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) from the opening (510). This reduces the possibility of blocking smoke from entering the room.

The sensor (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) according to the nineteenth aspect includes a smoke detection chamber (4) in any one of the first to eighteenth aspects. It further includes an upper cover (52, 53) arranged to cover from above. The dividing part (Z1) includes branch parts (71, 71A, 71B). The branch part (71, 71A, 71B) divides the space (SP1) around the smoke detection chamber (4) into two in a separation direction (A1) including a vertical direction (A2) component, and connects the upper flow path (61). and a lower flow path (62). The branch part (71, 71A, 71B) directs the smoke that has passed through the upper channel (61) of the upper channel (61) and the lower channel (62) from the inlet (40) to the smoke detection chamber ( 4). The upper cover (52, 53) forms a part of the upper flow path (61) of the upper flow path (61) and the lower flow path (62). According to the nineteenth aspect, the number of parts can be reduced compared to the case where the member forming the upper channel (61) is provided separately from the upper cover (52). It also becomes easier to achieve miniaturization (particularly lower height).

The configurations according to the second to nineteenth aspects are not essential to the sensors (1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H) and can be omitted as appropriate.

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H Sensor 2, 2A Base 202 Inclined part 22 2nd surface (bottom surface)
23 Outer peripheral part 24 Recessed part 25 Projecting edge part 30 Heat detection element 4 Smoke detection chamber 40 Inflow port 41 Peripheral wall 411 First area 412 Second area 51 Lower cover 510, 510A Opening part 511 Cylindrical part 52, 53 Upper cover 6 Channel 61 Upper channel 62 Lower channel 71, 71A, 71B Branch section 72 Blocking section 73 Notch A1 Separation direction A2 Vertical direction SP1 Surrounding space SP2 External space SP3 First space SP4 Second space SP5 Third space Z1 Dividing section

Claims (20)

a smoke detection chamber having an inlet through which smoke flows;
an opening that communicates an external space with a space around the smoke detection chamber;
a dividing portion arranged in the surrounding space to surround the smoke detection chamber and dividing a gas flow path;
The dividing portion has a first inflow amount of smoke flowing into the gas flow path from the opening and a second inflow amount of steam flowing into the gas flow path from the opening.
the gas such that a first ratio of the amount of smoke reaching the inlet to the first inflow amount is higher than a second ratio of the amount of steam reaching the inlet to the second inflow amount; divide the flow path of
sensor. The dividing portion includes a branching portion that divides the space around the smoke detection chamber into two in a separation direction including a vertical component and branches into two, an upper flow path and a lower flow path,
The branch part causes smoke that has passed through the upper flow path of the upper flow path and the lower flow path to flow into the smoke detection chamber from the inflow port.
The sensor according to claim 1. further comprising a blocking part disposed between the lower flow path and the smoke detection chamber to block steam passing through the lower flow path from flowing into the smoke detection chamber;
The sensor according to claim 2. The branch part is formed around the entire circumference of the smoke detection chamber,
The sensor according to claim 2 or 3. The peripheral wall of the smoke detection chamber is
a first region in which the inlet is formed;
a second region in which the inflow port is not formed;
The branch part has a notch at a position facing the second region,
The sensor according to any one of claims 2 to 4. The dividing portion forms a first space, a second space, and a third space that are flow paths for the gas,
The external space and the first space, the first space and the second space, and the second space and the third space are adjacent to each other in one direction from the opening toward the smoke detection chamber,
Regarding the first inflow amount of smoke and the second inflow amount of steam, in the third space, the first proportion of the smoke is higher than the second proportion of the steam,
The volume of the second space is larger than the volume of each of the first space and the third space.
The sensor according to any one of claims 1 to 5. a smoke detection chamber having an inlet through which smoke flows;
an opening that communicates an external space with a space around the smoke detection chamber;
comprising a dividing part arranged in the space around the smoke detection chamber and dividing a gas flow path,
The dividing portion forms a first space, a second space, and a third space in the gas flow path,
The external space and the first space, the first space and the second space, and the second space and the third space are adjacent to each other in one direction from the opening toward the smoke detection chamber,
The dividing portion has a first inflow amount of smoke flowing into the gas flow path from the opening and a second inflow amount of steam flowing into the gas flow path from the opening.
the gas such that a first ratio of the amount of smoke reaching the inlet to the first inflow amount is higher than a second ratio of the amount of steam reaching the inlet to the second inflow amount; divide the flow path of
Regarding the first inflow amount of smoke and the second inflow amount of steam, in the third space, the first proportion of the smoke is higher than the second proportion of the steam,
In the cross section along the one direction and the vertical direction,
The cross-sectional area of the second space is larger than each of the cross-sectional areas of the first space and the third space.
sensor. In the cross section along the one direction and the vertical direction,
The length in the vertical direction of the second space is longer than the length in the vertical direction of each of the first space and the third space.
The sensor according to claim 6 or 7. In the cross section along the one direction and the vertical direction,
The length of the second space in the one direction is longer than each of the lengths of the first space and the third space in the one direction.
The sensor according to any one of claims 6 to 8. The dividing portion includes a slope between the second space and the third space that slopes vertically upward as it approaches the smoke detection chamber in the one direction.
The sensor according to any one of claims 6 to 9. further comprising an airflow control unit that is arranged vertically above the outer periphery of the opening and controls the gas to flow into the opening;
The sensor according to any one of claims 1 to 10. The airflow control unit divides the main airflow containing smoke or steam in the external space into a first airflow that does not flow into the gas flow path from the opening and a second airflow that flows into the gas flow path from the opening. The ratio of the amount of smoke in the second airflow to the amount of smoke in the first airflow when the main airflow contains smoke is the ratio of the amount of smoke in the second airflow to the amount of smoke in the first airflow when the main airflow contains steam. controlling the main airflow so that the ratio of the amount of steam in the second airflow to the amount of steam is higher;
The sensor according to claim 11. further comprising a base on which the smoke detection chamber is mounted;
The sensor according to any one of claims 1 to 12. the base is a circuit board;
The sensor according to claim 13. further comprising one or more heat sensing elements arranged on the outer periphery of the base;
The sensor according to claim 13 or 14. The outer peripheral portion has a concave portion recessed inward in a peripheral region where the heat sensing element is arranged.
The sensor according to claim 15. a smoke detection chamber having an inlet through which smoke flows;
a base on which the smoke detection chamber is mounted;
a cylindrical portion arranged to cover the lower surface of the base ;
an opening that communicates an external space with a space around the smoke detection chamber;
comprising a dividing part arranged in the space around the smoke detection chamber and dividing a gas flow path,
The base has a protruding edge that protrudes outward from the cylindrical part,
The dividing portion has a first inflow amount of smoke flowing into the gas flow path from the opening and a second inflow amount of steam flowing into the gas flow path from the opening.
the gas such that a first ratio of the amount of smoke reaching the inlet to the first inflow amount is higher than a second ratio of the amount of steam reaching the inlet to the second inflow amount; divide the flow path of
sensor. further comprising a lower cover that has an opening that communicates an external space with a space around the smoke detection chamber and is disposed below the base;
The outer peripheral portion of the base does not protrude into the external space from the opening when looking at the lower cover from the front.
The sensor according to any one of claims 13 to 17. a smoke detection chamber having an inlet through which smoke flows;
an upper cover arranged to cover the smoke detection chamber from above ;
an opening that communicates an external space with a space around the smoke detection chamber;
comprising a dividing part arranged in the space around the smoke detection chamber and dividing a gas flow path,
The dividing portion includes a branching portion that divides the space around the smoke detection chamber into two in a separation direction including a vertical component and branches into two, an upper flow path and a lower flow path,
The branch part causes smoke that has passed through the upper flow path of the upper flow path and the lower flow path to flow into the smoke detection chamber from the inflow port,
The upper cover forms a part of the upper flow path of the upper flow path and the lower flow path ,
The dividing portion has a first inflow amount of smoke flowing into the gas flow path from the opening and a second inflow amount of steam flowing into the gas flow path from the opening.
the gas such that a first ratio of the amount of smoke reaching the inlet to the first inflow amount is higher than a second ratio of the amount of steam reaching the inlet to the second inflow amount; divide the flow path of
sensor. A sensor according to any one of claims 1 to 19,
a receiver in communication with the sensor;
Fire alarm system.

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