JP2024091771A - Detectors and automatic fire alarm systems - Google Patents

Abstract

[Problem] To achieve miniaturization.
[Solution] The detector 1 includes a substrate 2, a heat detection element 30, and a housing 5. The housing 5 houses the substrate 2. The housing 5 has a flow path 6 provided in an internal space SP1 thereof through which gas flows, and an opening 7 connecting the flow path 6 to an external space SP2 of the housing 5. The heat detection element 30 is a chip thermistor mounted on the substrate 2 and detects the heat of the gas that flows in from the opening 7.
[Selected Figure] Figure 1

Description

This disclosure relates generally to detectors and automatic fire alarm systems, and more specifically to detectors that detect heat generated by, for example, a fire, and an automatic fire alarm system equipped with such detectors.

As a conventional example, the combined heat and smoke detector described in Patent Document 1 is exemplified. This detector comprises a heat detection means for detecting heat, and a smoke detection section for detecting smoke that has flowed into the dark box. The heat detection means comprises a lead wire connected to a circuit board and protruding upward from the circuit board, and a heat-sensitive element such as a thermistor attached to the upper end of the lead wire.

JP 2012-014330 A

In the detector of Patent Document 1, the heat-sensitive element is provided at the upper end of the lead wire, which may make it difficult to miniaturize the detector as a whole (especially to make it thinner) depending on the length of the lead wire.

This disclosure has been made in consideration of the above-mentioned reasons, and aims to provide a detector and an automatic fire alarm system that can be made smaller.

A detector according to an aspect of the present disclosure includes a substrate, a heat detection element, and a housing. The housing accommodates the substrate. The housing has a flow path provided in an internal space thereof through which a gas flows, an opening connecting the flow path to an external space of the housing, and a smoke detector disposed in the internal space and detecting smoke. The heat detection element is a chip thermistor mounted on the substrate and detecting heat of the gas flowing in through the opening.
An automatic fire alarm system according to one aspect of the present disclosure includes the above-described sensor and a receiver that communicates with the sensor.

The present disclosure has the advantage of enabling miniaturization.

FIG. 1 is a cross-sectional view of a sensor according to a first embodiment. FIG. 2 is a perspective view of the sensor as viewed from below. Fig. 3A is a partially see-through plan view of the sensor, and Fig. 3B is an enlarged plan view of a main part of Fig. 3A. FIG. 4 is a schematic block diagram of the sensor. FIG. 5 is an enlarged front view of the opening of the sensor. FIG. 6 is a schematic cross-sectional view of a first modified example of the sensor. FIG. 7 is a schematic cross-sectional view of a second modified example of the sensor. Fig. 8A is a perspective view of the sensor according to the third modification from below, and Fig. 8B is a partially see-through plan view of the sensor according to the third modification. Fig. 9A is a perspective view of the fourth modified example of the sensor as viewed from below, and Fig. 9B is a partially see-through plan view of the fourth modified example of the sensor as viewed from below. Fig. 10A is a perspective view of the sensor according to the fifth modification from below, and Fig. 10B is a partially see-through plan view of the sensor according to the fifth modification. FIG. 11 is a perspective view of another modified example of the sensor as viewed from below. Fig. 12A is a side view of a main part of a sensor according to embodiment 2. Fig. 12B is a cross-sectional view of the main part of the sensor taken along the horizontal direction. Fig. 13A is a side view of a main part of the sensor according to the first modification, Fig. 13B is a cross-sectional view of the main part of the sensor according to the first modification along the horizontal direction, Fig. 13C is a cross-sectional view of the main part of another example of the sensor according to the first modification along the horizontal direction. Fig. 14A is a side view of a main part of the sensor according to the second modification, Fig. 14B is a cross-sectional view of the main part of the sensor according to the second modification taken along the horizontal direction, Fig. 14C is a perspective view of the main part of the sensor according to the second modification. FIG. 15 is an exploded perspective view of a main part of the second modified example. FIG. 16 is a side view of a main part of the above sensor according to a third modified example. 17A and 17B are side and horizontal sectional views of the main parts of the sensor according to the fourth modification, respectively; Fig. 18A is a perspective view of the sensor according to embodiment 3 as viewed from below, Fig. 18B is a partially see-through plan view of the sensor, and Fig. 18C is a vertical cross-sectional view of a main part of the sensor near an inlet. Fig. 19A is a diagram showing a state in which a tester is used to perform a heating inspection on the above-mentioned sensor installed in a structure, and Fig. 19B is a schematic cross-sectional view of the tester in a state in which the above-mentioned sensor is covered with the tester. FIG. 20 is a perspective view of a modification of the sensor as viewed from below. Fig. 21A is a perspective view showing a state in which a main body of a sensor according to embodiment 4 is directly attached to a structure using a mounting base, and Fig. 21B is an exploded perspective view of the main body of the sensor and the mounting base. Fig. 22A is a perspective view showing a state in which the main body of the sensor is embedded in a structure using an embedding base, and Fig. 22B is an exploded perspective view of the main body of the sensor and the embedding base. 23A and 23B are partial cross-sectional views each showing a state in which the embedding base is attached to a structure using a first mounting bracket and a second mounting bracket, respectively.

(Embodiment 1)
(1) Overview Each drawing described in the following embodiments is a schematic drawing, and the ratio of sizes and thicknesses of each component in each drawing does not necessarily reflect the actual dimensional ratio.

The detector 1 of this embodiment is, for example, a fire detector, and is equipped with a heat detection element 30 that detects heat generated by a fire or the like. In other words, the detector 1 is a detector that has at least the function of detecting heat. In the following, as an example, the detector 1 is assumed to be a so-called combined fire detector that further includes a smoke detection unit 4 (see FIG. 1) (see FIGS. 1 to 5). Instead of or in addition to the smoke detection unit 4, the detector 1 may be equipped with a detection unit that detects flames, gas leaks, or the generation of CO (carbon monoxide) due to incomplete combustion.

As shown in FIG. 2, the detector 1 is installed on a structure X1 (the ceiling in the illustrated example), which is a construction material such as the ceiling or wall of a building.

As shown in Figures 1 to 3A, the detector 1 includes a substrate 2, one or more thermal detection elements 30, and a housing 5. In this example, the detector 1 includes four thermal detection elements 30.

The housing 5 houses the substrate 2. As shown in FIG. 1, the housing 5 has a flow path 6 provided in its internal space SP1 through which gas flows, and an opening 7 connecting the flow path 6 to the external space SP2 of the housing 5. In FIG. 1, the flow path 6 is shown diagrammatically with arrows to make the flow of gas easier to understand, but the void portion around the smoke detector 4 in the internal space SP1 can roughly correspond to the flow path 6. Also, here, as an example, the housing 5 has six openings 7 (only three are shown in FIG. 2).

The thermal detection element 30 in this embodiment is a chip thermistor that is mounted on the substrate 2 and detects the heat of the gas that flows in through the opening 7, as shown in FIG. 1.

With this configuration, the thermal detection element 30 is a chip thermistor mounted on the substrate 2, so the detector 1 as a whole can be made smaller (especially thinner) than, for example, the configuration in Patent Document 1 in which the thermal element is provided at the upper end of the lead wire.

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

In the following, as in the example of Figure 2, it is assumed that the sensor 1 is installed on the ceiling surface (one surface of the structure X1). Accordingly, the up/down, left/right, front/back directions of the sensor 1 will be defined and explained using the up/down, left/right, front/back arrows shown in Figure 2. These arrows are merely provided to aid in the explanation and have no substance. Furthermore, these directions are not intended to limit the direction in which the sensor 1 can be used.

The detector 1 is equipped with a heat detection section 3 having the four heat detection elements 30 described above. In addition to the substrate 2, heat detection section 3, smoke detection section 4, and housing 5, the detector 1 further includes a display section 8 and a control section 9 (see FIG. 4). The detector 1 also includes a mounting section 10 for mounting to the structure X1 (see FIG. 1). In FIG. 1, the mounting structure (e.g., a disk-shaped mounting base) on the structure X1 side to which the mounting section 10 is fixed is not shown. The detector 1 is detachably mounted to the mounting base fixed to the structure X1.

When the detector 1 detects a fire, it transmits a signal to an external alarm device or the like (not shown) to notify the occurrence of the fire, and also has a communication unit 11 that receives signals from the alarm device or the like.

The detector 1 may be powered by a commercial power source or by a battery installed inside the housing 5.

(2.2) Housing The housing 5 accommodates the board 2, the heat detection unit 3, the smoke detection unit 4, the light source 81 of the display unit 8, the control unit 9, the communication unit 11, and other circuit modules, etc. The housing 5 also supports the guide unit 82 of the display unit 8 so that one surface of the guide unit 82 is exposed to the outside (see FIG. 2).

The housing 5 is made of synthetic resin, for example flame-retardant ABS resin. The housing 5 is generally formed into a cylindrical shape that is flat in the vertical direction. As shown in FIG. 1, the housing 5 has a cylindrical front cover 51 with one open side (the top side in the illustrated example), and a disk-shaped back cover 52. The housing 5 has an installation surface 55 (see FIG. 1) that faces the structure X1 to which the sensor 1 is attached. Here, one side (top surface) of the back cover 52 corresponds to the installation surface 55. The housing 5 is constructed by assembling the back cover 52 to the front cover 51 from the open side.

As described above, the housing 5 has a flow path 6 provided in its internal space SP1 through which gas flows, and six side openings (horizontal holes) 7A as six openings 7 connecting the flow path 6 with the external space SP2. In other words, the openings 7 have side openings 7A. There is no particular limit to the number of openings 7, but considering the flow of gas in and out of the housing 5, it is preferable that two or more openings are provided.

Here, six openings 7 (six side openings 7A) are provided in the front cover 51. Specifically, as shown in FIG. 1 and FIG. 2, the front cover 51 is composed of a flat cylinder 510 with both upper and lower ends open, a disk-shaped base 511 below the cylinder 510, and a plurality of (for example, six) ribs 512 connecting the cylinder 510 and the base 511. The cylinder 510, the base 511, and the six ribs 512 are integrally formed. The six ribs 512 are arranged at approximately equal intervals along the circumferential direction on the peripheral edge of the base 511, and protrude from the peripheral edge toward the open lower edge of the cylinder 510. The six ribs 512 maintain the distance between the cylinder 510 and the base 511 at a specified distance. The six openings 7 are arranged at approximately equal intervals along the circumferential direction on the peripheral wall of the front cover 51 configured in this manner.

Each opening 7 (each side opening 7A) is a roughly rectangular through-hole that penetrates the peripheral wall of the front cover 51 in the radial direction, and serves as an opening that connects the flow path 6 to the external space SP2.

The front cover 51 has a positioning structure for positioning the board 2 on the upper surface side of the base 511. As an example of the positioning structure, a positioning recess may be provided on the upper surface side of the base 511, and a tab protruding from the board 2 may be fitted into the recess. As shown in FIG. 3A, the base 511 has a diameter slightly larger than the diameter of the board 2.

The front cover 51 also has a pair of holes 513 (see FIG. 3A) in the base 511 for exposing one surface (lower surface) of the guide portion 82 of the display unit 8 to the external space SP2.

The pair of holes 513 are located near the periphery of the base 511 when the base 511 is viewed from below. The pair of holes 513 are arranged so as to be equally spaced in the circumferential direction of the base 511. In other words, the pair of holes 513 are arranged so that an imaginary line connecting them passes through the center of the base 511. The arrangement direction of the pair of holes 513 corresponds to the front-rear direction in this disclosure.

Each hole 513 penetrates the base 511 in its thickness direction (vertical direction). The opening of each hole 513 is approximately rectangular. A corresponding guide portion 82 is fitted into each hole 513. Therefore, the light emitted from the pair of light sources 81 is guided to the outside of the housing 5 via each of the pair of guide portions 82.

The rear cover 52 has a plurality of insertion holes 520 into which a plurality of (for example, four) connection pieces 101 of the mounting portion 10 fixed to the substrate 2 are inserted (see FIG. 1). The plurality of connection pieces 101 are electrically connected to the circuit module provided on the substrate 2. The plurality of connection pieces 101 are inserted to such an extent that their tips sufficiently protrude from the rear side (the installation surface 55 side) of the rear cover 52. The plurality of connection pieces 101 can be mechanically and electrically connected to the contact portion of the mounting base (not shown) fixed to the structure X1. In short, the mounting portion 10 is not only a part that simply provides a mechanical connection to the mounting base, but also an electrical connection with the electric wires (power supply line and signal line) on the rear side of the structure X1, and also a part that stably positions the substrate 2 relative to the rear cover 52. This positioning includes not only the radial positioning of the substrate 2, but also the vertical positioning of the substrate 2.

The rear cover 52 also has a storage recess 521 (see FIG. 1) on one surface (lower surface) facing the board 2 for storing the upper part of the smoke detection unit 4 mounted on the board 2. In other words, the smoke detection unit 4 is stably positioned by the storage recess 521.

Furthermore, the rear cover 52 has a plurality of control plates (walls) 522 (see FIG. 3A: four in the illustrated example) on one surface (lower surface) facing the substrate 2, which controls the flow of gas in the flow path 6. Each control plate 522 is formed in an approximately arc shape when viewed from the substrate 2 side. Each control plate 522 protrudes in a direction approaching the base 511 of the front cover 51 (downward). The four control plates 522 are arranged at approximately equal intervals along the circumferential direction of the rear cover 52 near the peripheral edge of the rear cover 52 when viewed from the substrate 2 side. The four control plates 522 control (guide) the airflow in the internal space SP1 of the housing 5 so that the gas flowing through the flow path 6 flows more easily toward the heat detection element 30 or the smoke detection unit 4. The number of control plates 522 is not particularly limited and may be one.

(2.3) Board The board 2 is a printed circuit board. The board 2 is equipped with a heat detection unit 3, a smoke detection unit 4, a display unit 8, a control unit 9, a communication unit 11, and other circuit modules (not shown). The other circuit modules include a lighting circuit that lights up the light source 81 of the display unit 8 and the optical element 41 of the smoke detection unit 4, and a power supply circuit that generates operating power for various circuits using power supplied from a commercial power source or the like.

As shown in FIG. 3A, the substrate 2 is formed in a generally circular shape as a whole. FIG. 3A is a plan view of the detector 1 as seen from below, with some parts (substrate 2, control plate 522, and smoke detector 4) being transparent.

In this embodiment, at least four heat detection elements 30 of the heat detection unit 3 are surface-mounted on the first surface 21 (front surface) of the substrate 2. The first surface 21 is the top surface (see FIG. 1). As an example, the smoke detection unit 4 is also arranged on the same plane as the first surface 21 of the substrate 2. The smoke detection unit 4 is mounted on the first surface 21 of the substrate 2. The labyrinth portion 43 (described later) of the smoke detection unit 4 has an engagement claw on the underside of its bottom, and is fixed by engaging the engagement claw with an engagement hole formed in the substrate 2. The light source 81 of the display unit 8 is also mounted on the first surface 21 of the substrate 2.

The control unit 9 and the multiple electronic components that make up the circuit module are mounted on the first surface 21 or the second surface 22 of the substrate 2. The control unit 9 and the multiple electronic components that make up the circuit module do not have to be mounted only on the substrate 2; for example, another mounting substrate may be disposed around the substrate 2, and some or all of the electronic components may be mounted on that mounting substrate.

Hereinafter, the surface of the substrate 2 opposite the first surface 21 (top surface) may be referred to as the second surface 22 (bottom surface). In FIG. 3A, the substrate 2 is made transparent, and its second surface 22 is visible. The heat detection element 30, light source 81, and smoke detection unit 4 are actually mounted on the first surface 21 behind the second surface 22, but for ease of explanation, these are also shown in transparent form in FIG. 3A. In particular, in FIG. 3A, the optical element 41 and light receiving element 42 arranged in the labyrinth portion 43 of the smoke detection unit 4 are shown simplified with dots.

Of the first surface 21 and the second surface 22, the first surface 21 corresponds to the surface closer to the installation surface 55. Therefore, it can be said that both the heat detection element 30 and the smoke detection unit 4 are disposed on the surface of the substrate 2 closer to the installation surface 55.

The structure of the substrate 2 will be described in detail below. As shown in FIG. 3A, the substrate 2 has a circular main body 200 and multiple (eight in the illustrated example) extending portions that extend away from the center of the main body 200 at the edge of the main body 200. Hereinafter, the eight extending portions will be referred to as a pair of first extending portions 201, a pair of second extending portions 202, a pair of third extending portions 203, and a pair of fourth extending portions 204.

The smoke detector 4 is disposed on the top surface of the main body 200. Meanwhile, the four heat detector elements 30 and the two light sources 81 are disposed on the six extensions (201, 202, 203), respectively.

The pair of first extension portions 201 extend away from each other from the left and right edges of the main body portion 200. A corresponding connection piece 101 is disposed on the upper surface of each first extension portion 201. Each first extension portion 201 also has a narrower small piece portion Y1 at its tip. A corresponding heat detection element 30 is disposed on the upper surface of each small piece portion Y1.

The pair of second extension parts 202 extend away from each other from the front and rear edges of the main body part 200. The extension amount of the second extension part 202 is less than the extension amount of the other extension parts. A corresponding light source 81 is disposed on the upper surface of each second extension part 202.

When viewed from the underside of the substrate 2, the pair of third extension portions 203 extend away from each other from positions slightly offset in the counterclockwise direction from the front and rear edges of the main body portion 200. Specifically, the front third extension portion 203 is disposed to the left of the front second extension portion 202, and the rear third extension portion 203 is disposed to the right of the rear second extension portion 202. Like the first extension portion 201, each third extension portion 203 also has a narrower small piece portion Y1 at its tip. A corresponding thermal detection element 30 is disposed on the upper surface of each small piece portion Y1.

When viewed from the underside of the substrate 2, the pair of fourth extension portions 204 extend away from each other from positions slightly offset in the clockwise direction from the front and rear edges of the main body portion 200. Specifically, the front fourth extension portion 204 is disposed to the right of the front second extension portion 202, and the rear fourth extension portion 204 is disposed to the left of the rear second extension portion 202. A corresponding connection piece 101 is disposed on the upper surface of each fourth extension portion 204.

In short, the substrate 2 has a shape that is two-fold symmetrical, i.e., it becomes symmetrical when rotated 180 degrees around its center.

Meanwhile, a pair of first extensions 201 and a pair of third extensions 203 in which four thermal detection elements 30 are arranged are each provided with a through hole 31 (see FIG. 3B) having a rectangular opening. FIG. 3B is an enlarged view of a circle surrounded by a dotted line (imaginary line) in FIG. 3A as an example. The through hole 31 is arranged inside the thermal detection element 30 (toward the center of the internal space SP1). The thermal detection element 30 and the through hole 31 are arranged adjacent to each other. By providing such a through hole 31 near each thermal detection element 30, the area occupied by the substrate 2 around the thermal detection element 30 can be reduced, and the heat in the thermal detection element 30 can be prevented from being transferred through the substrate 2 and becoming lower. That is, the through hole 31 improves thermal insulation. It is desirable that the opening area of the through hole 31 is larger than the surface area of the thermal detection element 30 (for example, the surface area seen from the top side of the substrate 2).

(2.4) Heat detection unit and smoke detection unit As described above, the heat detection unit 3 has four heat detection elements 30 mounted on the first surface 21 of the substrate 2 (only one is shown in FIG. 4). The number of heat detection elements 30 is not particularly limited and may be one, but is preferably at least two or more. In this embodiment, the heat detection elements 30 are chip thermistors that detect the heat of the gas flowing in from the openings 7, and are surface-mounted on the substrate 2. Each heat detection element 30 is disposed so as to face one different opening 7. The positional relationship of the heat detection elements 30 with respect to the flow path 6 and the openings 7 will be described in detail in the section "(2.7) Layout structure of heat detection unit" below.

The heat detection unit 3 is electrically connected to the control unit 9 via pattern wiring formed on the substrate 2. Each heat detection element 30 outputs an electrical 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 may 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 amplifier circuit that amplifies the electrical signal from the heat detection element 30 and a conversion circuit that performs analog-to-digital conversion, or the amplification and conversion may be performed on the circuit module side.

The smoke detector 4 is disposed in the center of the internal space SP1 and is configured to detect smoke. Specifically, the smoke detector 4 is disposed on the upper surface of the main body 200 of the substrate 2, and its upper portion is housed in the accommodation recess 521 of the rear cover 52. The smoke detector 4 is, for example, a photoelectric sensor that detects smoke. As shown in FIG. 4, the smoke detector 4 has an optical element 41 that emits light, a light receiving element 42 that receives the light emitted from the optical element 41, and a labyrinth portion 43. The optical element 41 is, for example, an LED (Light Emitting Diode). The light receiving element 42 is, for example, a photodiode. The labyrinth portion 43 is formed inside a case having a flat, approximately cylindrical outer shell. The case of the smoke detector 4 has a plurality of openings on its outer circumferential surface that introduce gas into the labyrinth portion 43, and has a structure that suppresses external light from entering the inside.

The optical element 41 and the light receiving element 42 are arranged so as not to face each other within the labyrinth portion 43. In other words, the light receiving surface of the light receiving element 42 is arranged so as to be off the optical axis C1 (see FIG. 3A) of the light emitted by the optical element 41.

In the event of a fire or other incident, smoke may enter the housing 5 through the opening 7 of the housing 5 and be introduced into the labyrinth section 43. If there is no smoke in the labyrinth section 43, very little of the light emitted by the optical element 41 reaches the light receiving surface of the light receiving element 42. On the other hand, if there is smoke in the labyrinth section 43, the light emitted by the optical element 41 is scattered by the smoke, and some of the scattered light reaches the light receiving surface of the light receiving element 42. In other words, the smoke detection unit 4 receives the light emitted by the optical element 41 that has been scattered by the smoke at the light receiving element 42.

The light receiving element 42 of the smoke detection unit 4 is electrically connected to the control unit 9. The smoke detection unit 4 transmits an electrical signal (detection signal) indicating a voltage level corresponding to the amount of light received by the light receiving element 42 to the control unit 9. The control unit 9 converts the amount of light of the detection signal received from the smoke detection unit 4 into smoke concentration to determine whether or not there is a fire. The control unit 9 may use the amount of light directly for threshold determination. The smoke detection unit 4 may convert the amount of light received by the light receiving element 42 into smoke concentration and then transmit a detection signal indicating a voltage level corresponding to the smoke concentration to the control unit 9.

The smoke detector 4 may further include an amplifier circuit that amplifies the electrical signal from the light receiving element 42 and a converter circuit that performs analog-to-digital conversion, or the amplification and conversion may be performed on the circuit module side. In addition, the number of optical elements 41 for smoke detection is not limited to one, and may be multiple.

(2.5) Display The display 8 has a pair of light sources 81 and a pair of guides 82. Each light source 81 is configured 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. As described above, each light source 81 is mounted on the board 2. Each guide 82 is a translucent portion formed in a substantially L-shape. Each guide 82 faces the corresponding light source 81 on the board 2 and has an incident surface on which light emitted from the light source 81 is incident. Each guide 82 has an exit surface on which the light incident from the incident surface is emitted to the outside of the guide 82. The exit surface of each guide 82 is exposed through the corresponding hole 513 of the front cover 51.

The display unit 8 is an operating light that notifies the outside of the operating state of the detector 1. Under normal circumstances (when monitoring for a fire), the lighting circuit of the circuit module turns off the light source 81 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 to blink or light the light source 81 under the control of the control unit 9. In Figure 4, the lighting circuit between the control unit 9 and the display unit 8 is not shown.

(2.6) Control Unit The control unit 9 is configured, for example, by a microcontroller mainly composed of a CPU (Central Processing Unit) and a memory. In other words, the control unit 9 is realized by a computer having a CPU and a memory, and the computer functions as the control unit 9 by the CPU executing a program stored in the memory. Here, the program is pre-recorded in the memory, but it may be provided through a telecommunication line such as the Internet, or recorded on a recording medium such as a memory card.

The control unit 9 is configured to control the communication unit 11 and the circuit modules (lighting circuits, power supply circuits, etc.).

The control unit 9 is also configured to receive detection signals from the heat detection unit 3 and the smoke detection unit 4 and determine whether or not a fire has occurred. Specifically, the control unit 9 individually monitors the detection signals from the four heat detection elements 30 of the heat detection unit 3, and determines that a fire has occurred if at least one heat detection element 30 is found whose signal level (corresponding to a resistance value) contained in the detection signal exceeds (or falls below) a threshold value. The control unit 9 also monitors the detection signal from the smoke detection unit 4, and determines that a fire has occurred if the signal level (corresponding to the amount of light received by the light receiving element 42 or smoke concentration) contained in the detection signal exceeds a threshold value.

When the control unit 9 determines that a fire has occurred based on heat detection or smoke detection, it transmits a signal notifying the occurrence of a fire to the receiver and fire alarm of the automatic fire alarm system via the communication unit 11. The communication unit 11 is a communication interface for communicating with the receiver and fire alarm, for example, via a wire. The communication unit 11 is communicatively connected to the receiver and fire alarm via the connection piece 101 of the mounting unit 10, the connector part of the mounting base, and a signal line wired to the back side of the structure X1. Furthermore, when the control unit 9 determines that a fire has occurred, it outputs a control signal to the lighting circuit of the circuit module to blink or light the light source 81 of the display unit 8 (operation light).

(2.7) Arrangement of the Heat Detection Unit The arrangement of the heat detection unit 3 of this embodiment will now be described.

In this embodiment, as described above, the thermal detection element 30 of the thermal detection unit 3 is a chip thermistor mounted on the first surface 21 of the substrate 2. This allows the detector 1 as a whole to be made smaller (particularly thinner). In addition, compared to lead-type thermistors, the cost of the thermistor itself and its mounting cost can be kept low.

Furthermore, in this embodiment, at least a portion of the first surface 21 (surface) of the substrate 2 is exposed to the flow path 6. Here, the smoke detection unit 4 is disposed in the center of the first surface 21, and the central portion of the internal space SP1 of the housing 5 is mostly occupied by the smoke detection unit 4. The flow path 6 essentially corresponds to the space surrounding the central portion (smoke detection unit 4) of the internal space SP1. In other words, the flow path 6 is roughly donut-shaped. Therefore, in this embodiment, of the entire area of the first surface 21 of the substrate 2, the peripheral area other than the mounting area of the smoke detection unit 4 is exposed to the flow path 6. The peripheral area also includes the upper surfaces of the total of eight extensions (201-204) described above.

By exposing the peripheral area of the first surface 21 of the substrate 2 to the flow path 6 in this manner, the four thermal detection elements 30 in the first extension portion 201 and the third extension portion 203, although they are chip thermistors, are more likely to be exposed to the gas flowing through the flow path 6.

That is, for example, when hot gas rises from below due to the outbreak of a fire or the like, it is introduced into the housing 5 through the multiple openings 7 and flows through the flow path 6. At that time, the heat detection element 30 detects heat at a temperature equivalent to a fire, and the detector 1 can quickly determine that a fire has occurred. As a result, the detector 1 can be made smaller while still improving its heat detection performance.

The detector 1 of this embodiment further includes a smoke detection unit 4, which is located in the center of the internal space SP1 at the back of the flow path 6. In other words, the flow path 6 is a common flow path through which both heat and smoke can pass. Therefore, if the gas introduced into the housing 5 from the multiple openings 7 has a smoke concentration equal to or greater than a specified level, smoke can also be detected. This makes it possible to reduce the overall size of the detector 1 while improving fire detection performance.

In this embodiment, each thermal detection element 30, which is a chip thermistor, is arranged to face one different opening 7. In FIG. 1, the thermal detection element 30 on the left side is arranged to face one opening 7 on the left side, and the thermal detection element 30 on the right side is arranged to face another opening 7 on the right side. Each thermal detection element 30 is arranged to fit within a substantially rectangular opening area 70 when the opening area 70 (see FIG. 1 and FIG. 5) of the corresponding opening 7 is viewed from the external space SP2 side. In other words, the area of the thermal detection element 30 projected onto the opening area 70 fits within the opening area 70. Therefore, the possibility that at least a part of the thermal detection element 30 is exposed to the gas entering through the opening 7 can be increased compared to when the thermal detection element 30 is arranged outside the opening area 70, that is, hidden behind the cylinder 510 of the housing 5 or behind the crosspiece 512.

In particular, in this embodiment, as shown in FIG. 5, each thermal detection element 30, which is a chip thermistor, is located in the center of the opening region 70 in the direction (up-down direction) perpendicular to the first surface 21 when the opening region 70 is viewed from the external space SP2 side. In other words, the positional relationship between the opening 7 and the substrate 2 is specified so that each thermal detection element 30 is located in the center of the opening region 70. This positional relationship is adjusted, for example, by the protrusion amount of the rib 514 (see FIG. 1) that protrudes from the back side of the base 511 of the front cover 51 and contacts the substrate 2, and the insertion amount of the connection piece 101 of the mounting part 10, etc. Due to such a positional relationship, the possibility that the thermal detection element 30 is exposed to gas that has entered through the opening 7 can be further increased, for example, compared to when the thermal detection element 30 is located closer to one end (closer to the upper end or lower end) of the opening region 70.

In this embodiment, each thermal detection element 30 is not simply disposed to the side of the smoke detection unit 4, but is disposed near the opening 7. In other words, if the flow path 6 is divided into a first path 61 on the side of the opening 7 and a second path 62 connected to the first path 61 and disposed on the side of the center of the internal space SP1, each thermal detection element 30, which is a chip thermistor, is located in the first path 61 (see FIG. 1). Therefore, the responsiveness of the detector 1 with respect to heat detection can be improved compared to, for example, a case in which the chip thermistor is located in the second path 62. As described above, the flow path 6 is diagrammatically illustrated by an arrow line in FIG. 1, but in reality, the first path 61 corresponds to the outer half of the gap portion around the smoke detection unit 4 in the internal space SP1, and the second path 62 corresponds to the inner half of the gap portion.

Incidentally, in the thickness direction (vertical direction) of the substrate 2, the center P1 of the internal space of the labyrinth portion 43 is preferably located between the thermal detection element 30, which is a chip thermistor, and the installation surface 55 in the vertical direction (see FIG. 1). In other words, the thermal detection element 30 is located lower than the center P1 in the vertical direction. In FIG. 3A, the optical element 41 and the light receiving element 42 arranged in the labyrinth portion 43 are illustrated as schematic dots. In this embodiment, the heights of the optical element 41 and the light receiving element 42 are the same, and the intersection of the optical axis C1 of the optical element 41 and the optical axis C2 of the light receiving element 42 approximately coincides with the center P1, for example.

The height positions of the optical element 41 and the light receiving element 42 and the orientation of the optical axes C1 and C2 are not particularly limited, as long as the optical axis C1 does not intersect with the light receiving surface of the light receiving element 42. For example, the height of either the optical element 41 or the light receiving element 42 may be lower than the height of the other. Furthermore, the optical axes C1 and C2 do not have to intersect with each other. In this case, the midpoint between the optical axes C1 and C2 when viewed from the side of the smoke detection unit 4 may approximately coincide with the center P1.

Since center P1 is thus located between heat detection element 30 and installation surface 55, smoke (gas) that passes through heat detection element 30 can be effectively guided to smoke detection unit 4 in response to the characteristic that an ascending air current is generated when hot gas flows through flow path 6 inside housing 5. Therefore, in a detector 1 that detects not only heat but also smoke, it is possible to further improve the fire detection performance while miniaturizing the detector 1 as a whole.

(3) Modifications The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. In addition, a function similar to that of the sensor 1 according to the above embodiment may be embodied in a control method for the sensor 1, a computer program, or a non-transitory recording medium on which a computer program is recorded, etc.

Below, we will list some variations of the above embodiment. The variations described below can be combined as appropriate. In the following, the above embodiment may also be referred to as the "basic example."

The control unit 9 of the sensor 1 in the present disclosure includes a computer system. The computer system is mainly composed of a processor and a memory as hardware. The function of the control unit 9 of the sensor 1 in the present disclosure is realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, provided through an electric communication line, or recorded and provided in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by the computer system. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits such as IC or LSI referred to here are called differently depending on the degree of integration, and include integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, a field-programmable gate array (FPGA) that is programmed after the manufacture of the LSI, or a logic device that can reconfigure the connection relationship inside the LSI or reconfigure the circuit partition inside the LSI, can also be adopted as a processor. The multiple electronic circuits may be integrated into one chip, or may be distributed across multiple chips. The multiple chips may be integrated into one device, or may be distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

In addition, it is not essential for the sensor 1 that multiple functions in the control unit 9 of the sensor 1 are concentrated in one housing, and the components of the sensor 1 may be distributed across multiple housings. Furthermore, at least some of the functions of the sensor 1, for example, some of the functions of the sensor 1 may be realized by the cloud (cloud computing) or the like. Conversely, as in the basic example, multiple functions of the sensor 1 may be concentrated in one housing.

(3.1) Modification 1
The sensor 1A of this modified example (modified example 1) will be described below with reference to Fig. 6. Components that are generally common to the sensor 1 of the basic example are given the same reference numerals, and descriptions thereof may be omitted as appropriate. Fig. 6 shows a schematic cross-sectional view of the sensor 1A.

The detector 1A differs from the basic example in that it is provided with an airflow adjustment unit Z1 in the internal space SP1. The airflow adjustment unit Z1 extends from the lower edge of the cylinder 510 in the front cover 51 of the housing 5 toward the smoke detection unit 4. When viewed from the top and bottom, the airflow adjustment unit Z1 is a plate member that is roughly doughnut-shaped. The airflow adjustment unit Z1 may be formed integrally with the front cover 51, or may be a separate member from the front cover 51 and fixed to the front cover 51 by screws or the like.

The airflow adjustment section Z1 extends straight along the substrate 2 for a certain distance from the edge of the opening 7 toward the inside of the housing 5. However, the airflow adjustment section Z1 is inclined toward the installation surface 55 from the middle toward the center of the internal space SP1.

In other words, in the detector 1A, the airflow adjustment unit Z1 is provided, so that the opening cross-sectional area of the first path 61 is set smaller than the opening cross-sectional area of the second path 62. Therefore, the gas that has entered the flow path 6 through the opening 7 can be encouraged to flow from the first path 61, which is a narrow space, to the second path 62, which is a wide space.

In particular, because the airflow adjustment section Z1 is inclined from the middle in a direction approaching the installation surface 55, the second path 62 expands in a direction approaching the installation surface 55 as it moves from the first path 61 toward the center. Therefore, when hot gas flows through the flow path 6 in the housing 5, an ascending air current is generated, and the smoke (gas) that passes through the thermal detection element 30 can be effectively guided to the smoke detection section 4.

(3.2) Modification 2
The sensor 1B of this modified example (modified example 2) will be described below with reference to Fig. 7. Components that are generally common to the sensor 1 of the basic example are given the same reference numerals, and descriptions thereof may be omitted as appropriate. Fig. 7 shows a schematic cross-sectional view of the sensor 1B.

Detector 1B differs from the basic example in that the smoke detector 4 is mounted on the second surface 22 of the substrate 2, rather than on the first surface 21. The heat detector 30 is mounted on the first surface 21, as in the basic example.

In the housing 5 of this detector 1B, the smoke detection unit 4 is mounted on the second surface 22 (lower surface), and therefore the front cover 51 has a storage recess 515 for housing the smoke detection unit 4. Specifically, the base 511 of the front cover 51 is formed so that its center is convex downward. In the basic example, the back cover 52 has a storage recess 521 for housing the upper part of the smoke detection unit 4 (see FIG. 1).

The base 511 has a hole 5111 on the peripheral wall of the protruding portion 5110, which allows gas (smoke) to enter the housing 5.

The flow path 6 is configured to split into two, an upper flow path 6X and a lower flow path 6Y, with the substrate 2 as the boundary. Heated gas passing through the upper flow path 6X passes through the thermal detection element 30. A portion of the gas passing through the lower flow path 6Y passes through the through-hole 31 (see FIG. 3B) in the substrate 2, rises to the upper flow path 6X, and passes through the thermal detection element 30. The remainder of the gas passing through the lower flow path 6Y heads directly toward the smoke detection unit 4 in the center.

(3.3) Modification 3
The sensor 1C of this modified example (modified example 3) will be described below with reference to Figures 8A and 8B. Components that are generally common to the sensor 1 of the basic example will be given the same reference numerals and their description may be omitted as appropriate. Note that Figure 8A is a perspective view of the sensor 1C as seen from below, and Figure 8B is a plan view of the sensor 1C as seen from below, with a portion (only the substrate 2) being see-through.

As an example, detector 1C is a P-type heat detector that transmits a fire signal to the outside using a proprietary type (P) communication method. Detector 1C has a heat detection unit 3 like the basic example, but unlike the basic example does not have a smoke detection unit 4. In other words, detector 1C determines the occurrence of a fire or the like by detecting heat alone.

Detector 1C also differs from the basic example in that it has three heat detection elements 30 (four in the basic example).

As shown in FIG. 8B, the substrate 2 of the detector 1C is generally diamond-shaped when viewed from below. Two of the three heat detection elements 30 are surface-mounted on the first surface 21 (top surface) of the diamond-shaped substrate 2. The two heat detection elements 30 are disposed at diagonal positions in the left-right direction on the first surface 21 (top surface). Specifically, the substrate 2 has a pair of protrusions 23 that protrude outward (at a slight angle in the left-right direction) on both edges at the diagonal positions. A corresponding heat detection element 30 is disposed on the top surface of each protrusion 23. The other heat detection element 30 is disposed on the top surface of the central part of the substrate 2.

As in the basic example, a through hole 31 is provided near each thermal detection element 30 to improve thermal insulation. However, for the thermal detection element 30 located in the center of the substrate 2, two semicircular through holes 31 are arranged to sandwich the thermal detection element 30 between them.

The front cover 51 of the detector 1C has one inlet (vertical hole) 7B and two auxiliary ports (vertical holes) 56 at its base 511. The two auxiliary ports 56 are located near the left and right edges of the base 511, and the inlet 7B is located at the center of the base 511. The inlet 7B and the two auxiliary ports 56 each penetrate the base 511 of the front cover 51 in the thickness direction. The two auxiliary ports 56 located near the left and right edges of the base 511 have a roughly crescent-shaped opening, and the inlet 7B located at the center of the base 511 has a roughly circular opening. The pair of protrusions 23 of the substrate 2 face the two auxiliary ports 56 in a one-to-one correspondence, and the center of the substrate 2 faces the central inlet 7B. As a result, the convex portion 23 and the center of the substrate 2 are exposed from the two auxiliary ports 56 and the inlet 7B, respectively, as shown in FIG. 8B. Therefore, the rising hot gas enters the housing 5 through the two auxiliary ports 56 and the inlet 7B, and then flows through the through hole 31 to the first surface 21 (top surface) side. Therefore, the heat detection element 30 is easily exposed not only to the gas flowing in from the opening 7 (side port 7A: horizontal hole), but also to the gas flowing in from the two auxiliary ports 56 and the inlet 7B.

Even with this configuration, it is possible to further improve fire detection performance while making the detector 1C smaller (especially thinner) as a whole.

(3.4) Modification 4
A sensor 1D of this modified example (modified example 4) will be described below with reference to Figures 9A and 9B. Components that are generally common to the sensor 1 of the basic example will be given the same reference numerals, and their description may be omitted as appropriate. Note that Figure 9A is a perspective view of sensor 1D as seen from below, and Figure 9B is a plan view of sensor 1D as seen from below, with a portion (only substrate 2) being see-through.

As an example, detector 1D is an R-type heat detector that transmits a fire signal to the outside using a so-called R-type (Record-type) communication method. Detector 1D has a heat detection unit 3 like the basic example, but unlike the basic example does not have a smoke detection unit 4. In other words, detector 1D determines the occurrence of a fire or the like by detecting heat alone, like detector 1C of modification example 3.

Detector 1D also differs from the basic example in that it has five heat detection elements 30 (compared to four in the basic example).

As shown in FIG. 9B, the substrate 2 of the sensor 1D has a shape somewhat similar to that of the substrate 2 of the basic example. Specifically, the substrate 2 of the sensor 1D has a circular main body 200 and multiple (six in the illustrated example) extension parts that extend from the edge of the main body 200 in a direction away from the center of the main body 200. Hereinafter, the six extension parts are referred to as a pair of first extension parts 201, a pair of second extension parts 202, and a pair of third extension parts 203. One of the five thermal detection elements 30 is disposed in the center of the main body 200, and the remaining four thermal detection elements 30 and two light sources 81 are disposed in the six extension parts (201, 202, 203), respectively.

The pair of first extensions 201 extend away from each other from the left and right edges of the main body 200. Each first extension 201 has a narrower piece Y1 at its tip. A corresponding thermal detection element 30 is disposed on the top surface of each piece Y1.

The pair of second extension parts 202 extend away from each other from the front and rear edges of the main body part 200. The extension amount of the second extension part 202 is less than the extension amount of the other extension parts. A corresponding light source 81 is disposed on the upper surface of each second extension part 202.

When viewed from the underside of the substrate 2, the pair of third extension portions 203 extend away from each other from positions slightly offset in the counterclockwise direction from the front and rear edges of the main body portion 200. Specifically, the front third extension portion 203 is disposed to the left of the front second extension portion 202, and the rear third extension portion 203 is disposed to the right of the rear second extension portion 202. Like the first extension portion 201, each third extension portion 203 also has a narrower small piece portion Y1 at its tip. A corresponding thermal detection element 30 is disposed on the upper surface of each small piece portion Y1.

In short, the substrate 2 of the sensor 1D has, as an example, a two-fold symmetric shape that becomes symmetric when rotated 180 degrees around its center.

Also, as in the basic example, a through hole 31 is provided near each thermal detection element 30 to improve thermal insulation. However, for the thermal detection element 30 located in the center of the substrate 2, two semicircular through holes 31 are arranged to sandwich the thermal detection element 30 therebetween.Also, as in the basic example, a pair of guide portions 82 of the display unit 8 are exposed on the front cover 51 of the detector 1D.

The front cover 51 of the detector 1D has one inlet (vertical hole) 7B and two auxiliary ports (vertical holes) 57 at its base 511. The two auxiliary ports 57 are located near both the left and right edges of the base 511, and the inlet 7B is located at the center of the base 511. The two auxiliary ports 57 and the inlet 7B each penetrate the base 511 of the front cover 51 in the thickness direction. The two auxiliary ports 57 located near both the left and right edges of the base 511 have approximately rectangular openings, and the inlet 7B located at the center of the base 511 has an approximately circular opening. The tips of the small pieces Y1 in the pair of first extensions 201 of the substrate 2 face the two auxiliary ports 57 on the left and right in a one-to-one correspondence, and the center of the substrate 2 faces the central inlet 7B. As a result, the tip of the small piece Y1 and the center of the substrate 2 are exposed from the two auxiliary ports 57 and the inlet 7B, respectively, as shown in FIG. 9B. Therefore, the rising hot gas enters the housing 5 through the two auxiliary ports 57 and the inlet 7B, and then flows through the through hole 31 to the first surface 21 (top surface) side. Therefore, the heat detection element 30 is easily exposed not only to the gas flowing in from the opening 7 (side port 7A: horizontal hole), but also to the gas flowing in from the two auxiliary ports 57 and the inlet 7B.

Even with this configuration, it is possible to further improve fire detection performance while making the detector 1D smaller (especially thinner) as a whole.

(3.5) Modification 5
The sensor 1E of this modified example (modified example 5) will be described below with reference to Figures 10A and 10B. Components that are generally common to the sensor 1 of the basic example will be given the same reference numerals and their description may be omitted as appropriate. Note that Figure 10A is a perspective view of the sensor 1E seen from below, and Figure 10B is a plan view of the sensor 1E seen from below with a portion (only the substrate 2) being see-through.

As an example, detector 1E is a fire alarm that outputs an alarm sound or other sound when a fire occurs. Detector 1E has a heat detection unit 3 like the basic example, but unlike the basic example, it does not have a smoke detection unit 4. In other words, detector 1E determines the occurrence of a fire or other similar event by detecting heat alone, like detector 1C of modification 3 and detector 1D of modification 4.

Detector 1E also differs from the basic example in that it is equipped with a speaker that outputs sounds such as an alarm, and an audio circuit, etc. Detector 1E is also a battery-powered fire alarm, as an example. Therefore, detector 1E has a battery and a storage space for storing the battery, etc. In detector 1E, the operation unit U1 is exposed on the front of the front cover 51.

The operation unit U1 accepts operations from the outside. The operation unit U1 can be pushed upward by a user's finger or the like. The operation unit U1 is a translucent disc-shaped member. The operation unit U1 is disposed opposite an operation light inside the housing 5. The operation unit U1 is configured to press a push button switch inside the housing 5 when pushed. For example, if the operation unit U1 is pressed while an alarm sound is being issued, the output of the alarm sound is stopped. The operation unit U1 lights up when the detector 1E is in operation or when the battery runs out. Operation tests, etc. can also be performed by operating the operation unit U1.

Detector 1E also differs from the basic example in that it has three thermal detection elements 30 (four in the basic example).

As shown in FIG. 10B, the substrate 2 of the sensor 1E has an inverted Y shape when viewed from below. In the sensor 1E, components with relatively large volumes, such as a speaker, battery, and operation unit U1, are housed or supported within the housing 5, so in order to avoid these, the substrate 2 has an inverted Y shape that saves space.

Specifically, the substrate 2 of the detector 1E has a circular main body 200 with a notched left side, and multiple (three in the illustrated example) extending portions at the edge of the main body 200 that extend in a direction away from the center of the main body 200. Hereinafter, the three extending portions will be referred to as extending pieces 205. The three thermal detection elements 30 are respectively arranged on the three extending pieces 205.

Of the three extension pieces 205, the front extension piece 205 extends from the front edge of the main body 200, and a corresponding thermal detection element 30 is disposed on the upper surface of the tip of the extension piece 205. Of the three extension pieces 205, the rear two extension pieces 205 extend from a position slightly shifted to the left and right from the rear edge of the main body 200, and two corresponding thermal detection elements 30 are disposed on the upper surface of each of the tips.

As with the basic example, through holes 31 (three in total) are provided near the inner side of each thermal detection element 30 to improve thermal insulation.

The front cover 51 of the detector 1E has one auxiliary port (vertical hole) 58 at its base 511. The auxiliary port 58 is located near the front edge of the base 511. The auxiliary port 58 penetrates the base 511 of the front cover 51 in the thickness direction. The auxiliary port 58 has a substantially rectangular opening. The tip of the front extension piece 205 of the three extension pieces 205 faces the auxiliary port 58. As a result, the tip of the front extension piece 205 is exposed from the auxiliary port 58 as shown in FIG. 10B. Therefore, the rising hot gas enters the housing 5 through the auxiliary port 58 and further flows through the through hole 31 to the first surface 21 (upper surface) side. Therefore, the heat detection element 30 is easily exposed not only to the gas flowing in from the opening 7 (side port 7A: horizontal hole) but also to the gas flowing in from the auxiliary port 58.

Even with this configuration, it is possible to further improve fire detection performance while making the detector 1E smaller (especially thinner) as a whole.

(3.6) Other Modified Examples The detector 1 (combined fire detector) of the basic example does not have a vertical hole in the front cover 51, unlike the modified examples 3 to 5. However, similar to the modified examples 3 to 5, the detector 1 (combined fire detector) may have one or more auxiliary ports (vertical holes) 59 (two in the illustrated example) in the front cover 51, as shown in FIG.

In the basic example, the thermal detection element 30 is mounted on the first surface 21 (top surface) of the substrate 2. However, the thermal detection element 30 may also be mounted on the second surface 22 (bottom surface) of the substrate 2. Alternatively, some of the multiple thermal detection elements 30 may be mounted separately, with some on the first surface 21 and the rest on the second surface 22. Also, for example, both the thermal detection element 30 and the smoke detector 4 may be mounted on the second surface 22 (bottom surface) of the substrate 2.

In the basic example, the number of adjacent through holes 31 for one thermal detection element 30 is one, but as shown in modified examples 3 and 4, there may be two or more through holes 31. For example, multiple through holes 31 may be provided so as to surround one thermal detection element 30.

In the basic example, the thermal detection element 30 is mounted on the first surface 21 of the substrate 2, and the through holes 31 are arranged adjacent to each other. However, even if the thermal detection element 30 is mounted on the second surface 22 of the substrate 2, it is preferable that the through holes 31 are arranged adjacent to each other.

In the basic example, the substrate 2 is composed of one printed circuit board. However, the substrate 2 may be composed of two or more divided printed circuit boards. However, it is preferable that the divided multiple printed circuit boards are arranged on the same plane.

In the basic example, the opening 7 is a horizontal hole formed in the peripheral wall of the housing 5. However, the opening 7 in this disclosure may not be a horizontal hole, but may correspond to the inlet (vertical hole) 7B in Modifications 3 to 5, the auxiliary ports (vertical holes) 56 to 58, and the auxiliary port (vertical hole) 59 described above.

(Embodiment 2)
A sensor 1F according to this embodiment will be described below with reference to Figures 12A and 12B. The sensor 1F according to this embodiment differs from the sensor (1, 1A to 1E) of embodiment 1 (including modified examples) in that it further includes a shielding portion V1. Hereinafter, components substantially similar to those of embodiment 1 will be denoted by common reference numerals and descriptions thereof will be omitted as appropriate. The shielding portion V1 of this embodiment may also be applied to the sensor (1, 1A to 1E) of embodiment 1 as appropriate.

Note that detector 1F shown in Figures 12A and 12B is, as an example, a P-type heat detector, similar to detector 1C (Figures 8A and 8B) of modified example 3 in embodiment 1. Also, detector 1F is a heat detector that does not include a smoke detection unit 4, similar to detector 1C of modified example 3 in embodiment 1, and determines the occurrence of a fire or the like by detecting heat only.

In this embodiment, the thermal detection element 30 (chip thermistor) is also positioned so as to fit within the opening area 70 when the opening area 70 of the opening 7 (side opening 7A: horizontal hole) is viewed from the external space SP2 side. The shielding portion V1 is configured to block a portion of the opening area 70 on the external space SP2 side of the thermal detection element 30 (chip thermistor).

The shielding section V1 has a pair of pillars V11. Here, the shielding section V1 is composed of a pair of pillars V11. Each pillar V11 is long in the vertical direction (here, for example, the thickness direction of the substrate 2). Each pillar V11 is formed integrally with the front cover 51 of the housing 5. Specifically, the first end (upper end) of each pillar V11 is connected to the cylindrical body 510 of the housing 5, and the second end (lower end) of each pillar V11 is connected to the base 511. As a result, each pillar V11 extends from the upper edge to the lower edge of the opening 7 (side opening 7A).

When the opening area 70 is viewed from the external space SP2 side, the pair of pillars V11 are arranged with a predetermined distance L1 between them in a direction D1 (here, the left-right direction) perpendicular to the arrangement direction of the rear cover 52 and the front cover 51. In the following, as an example, the rear cover 52 corresponds to the first cover and the front cover 51 corresponds to the second cover, but the reverse may also be true, with the rear cover 52 corresponding to the second cover and the front cover 51 corresponding to the first cover.

Here, as an example, the predetermined distance L1 is a distance that is specified so that the test finger does not enter. The test finger is, for example, a dummy finger as specified in Appendix 4, 1 (2) (H) of the Electrical Appliance and Material Safety Act of Japan.

When the opening region 70 is viewed from the external space SP2 side, the heat detection element 30 is disposed between the pair of pillars V11 in the direction D1 (see FIG. 12A). In other words, the heat detection element 30 is exposed from between the pair of pillars V11.

In this way, by further providing the shielding portion V1, the detector 1F is less likely to be impeded from the inflow of heat from the opening 7, while reducing the possibility of, for example, a human finger or tool unintentionally touching the chip thermistor.

As shown in FIG. 12B, each pillar V11 has an induction surface V2 that induces the airflow from the external space SP2 toward the thermal detection element 30 (chip thermistor). Here, each pillar V11 has a cross-sectional shape cut along the horizontal direction that is approximately semi-elliptical, and the curved surface corresponds to the induction surface V2. The tip of the semi-elliptical shape faces the thermal detection element 30. This further reduces the possibility that the shielding portion V1 will prevent heat from entering through the opening 7.

Next, modified example 1 of this embodiment will be described. In the example of Figs. 12A and 12B described above, the number of pillars V11 of the shielding portion V1 is two, but the number of pillars of the shielding portion V1 is not particularly limited. Figs. 13A and 13B show a sensor 1G of modified example 1. Sensor 1G of modified example 1 differs from sensor 1F in that the number of pillars of the shielding portion V1 is three.

As an example, detector 1G of modified example 1 is a P-type heat detector. Note that, while the convex portion 23 of substrate 2 of detector 1F protrudes slightly obliquely with respect to the radial direction of housing 5 when viewed in the up-down direction (see FIG. 12B), the convex portion 23 of substrate 2 of detector 1G protrudes outward along the radial direction of housing 5 (see FIG. 13B).

The shielding section V1 of the detector 1G has three pillars (a pair of first pillars V12 on the left and right and a second pillar V13 in the middle). Here, the shielding section V1 is composed of three pillars. Each of the pair of first pillars V12 and second pillars V13 is long in the vertical direction (here, for example, the thickness direction of the substrate 2). Each of the pair of first pillars V12 and second pillars V13 is formed integrally with the front cover 51 of the housing 5. Specifically, the first end (upper end) of each pillar is connected to the cylinder 510 of the housing 5, and the second end (lower end) of each pillar is connected to the base 511. As a result, each pillar extends from the upper edge to the lower edge of the opening 7.

When viewing the opening area 70 from the external space SP2 side, each of the pair of first pillars V12 and the second pillar V13 is positioned with a predetermined distance L2 between them in the direction D1 (here, the left-right direction). Here, as an example, the predetermined distance L2 is also a distance that is specified so that a test finger cannot be inserted.

The heat detection element 30 is disposed between a pair of first pillars V12 in direction D1 when viewing the opening region 70 from the external space SP2 side (see FIG. 13A). However, when viewing the opening region 70 from the external space SP2 side, the heat detection element 30 is positioned so that it overlaps with the second pillar V13. In other words, the heat detection element 30 is positioned so that it is hidden behind the second pillar V13 and cannot be seen.

In this way, the detector 1G is provided with a shielding portion V1 having three pillars, which makes it difficult for heat to flow in from the opening 7 to be impeded, while further reducing the possibility of a human finger or tool coming into contact with the chip thermistor.

As shown in FIG. 13B, each of the pair of first columns V12 has an induction surface V2 that induces the airflow from the external space SP2 toward the thermal detection element 30 (chip thermistor). Here, each of the pair of first columns V12 has a cross-sectional shape cut along the horizontal direction that is a long, approximately racetrack shape that follows the outer edge of the housing 5, and has semicircular curved surfaces on both the left and right sides as induction surfaces V2. This further reduces the possibility that the shielding portion V1 will prevent heat from entering from the opening 7. Note that the cross-sectional shape of the second column V13 cut along the horizontal direction is approximately rectangular, but it may also have an approximately racetrack shape like the first column V12 and have an induction surface V2.

Note that FIG. 13C shows another example of the detector 1G of the first modification. In this other example, each of the pair of first pillars V12 has a cross-sectional shape cut along the horizontal direction that is approximately trapezoidal. Each first pillar V12 is configured so that, of the two parallel sides of the trapezoid, the short side is on the side of the thermal detection element 30 and the long side is on the side of the external space SP2. In particular, each first pillar V12 has a first surface V121 facing the second pillar V13 in the middle and a second surface V122 on the opposite side to the first surface V121 that are inclined toward the thermal detection element 30. The inclination angle of the second surface V122 with respect to the radial direction of the housing 5 is larger than the inclination angle of the first surface V121. The cross-sectional shape of the second pillar V13 in the middle cut along the horizontal direction is a bullet shape that is long in the radial direction of the housing 5, and the side facing the thermal detection element 30 is semicircular. In this other example, the first surface V121, the second surface V122, and the end surface having a semicircular cross section correspond to the guide surface V2. In other words, in this other example, each of the pair of first columns V12 has a guide surface V2. In this other example, the guide surface V2 is provided, so that the possibility that the shielding portion V1 will prevent heat from entering through the opening 7 can be further reduced.

Next, modified example 2 of this embodiment will be described. Figures 14A to 14C and Figure 15 show a sensor 1H of modified example 2. Sensor 1H of modified example 2 is an R-type heat sensor, as an example. The protrusion 23 of the substrate 2 of sensor 1H protrudes outward along the radial direction of the housing 5.

The shielding portion V1 in the sensor 1H of the second modification has a pair of first protrusions V14 and one second protrusion V15. Here, the shielding portion V1 is composed of a pair of first protrusions V14 and a second protrusion V15. Each of the pair of first protrusions V14 protrudes from the rear cover 52 (first cover) that covers the substrate 2 from one direction (here, from above) in the thickness direction of the substrate 2 toward the front cover 51 (second cover). The front cover 51 covers the substrate 2 from a direction opposite to the one direction in the thickness direction of the substrate 2 (here, from below). The second protrusion V15 protrudes from the front cover 51 toward the rear cover 52. Each of the pair of first protrusions V14 and second protrusions V15 is elongated along the up-down direction (here, for example, the thickness direction of the substrate 2).

As shown in FIG. 15, the pair of first protrusions V14 are formed integrally with the rear cover 52. Specifically, the pair of first protrusions V14 protrude downward continuously from the peripheral portion of the lower surface of the rear cover 52. Note that the tip of each of the pair of first protrusions V14 is not in contact with the front cover 51, and a gap is provided between the tip and the front cover 51.

The pair of first protrusions V14 are arranged at a predetermined distance L3 from each other in the direction D1 when the opening region 70 is viewed from the external space SP2 side. Here, as an example, the predetermined distance L3 is also a distance defined so that a test finger cannot be inserted. The thermal detection element 30 is arranged between the pair of first protrusions V14 in the direction D1 when the opening region 70 is viewed from the external space SP2 side (see FIG. 14A).

The second protrusion V15 is disposed in the center between the pair of first protrusions V14 in the direction D1. In other words, each of the pair of first protrusions V14 is disposed offset from the second protrusion V15 in the direction D1 when the opening region 70 is viewed from the external space SP2 side. This further reduces the possibility that the shielding portion V1 will prevent heat from entering from the opening 7.

The second protrusion V15 is formed integrally with the front cover 51. Specifically, the second protrusion V15 protrudes upward continuously from the peripheral edge of the top surface of the front cover 51. The tip of the second protrusion V15 is not in contact with the upper edge of the opening 7, leaving a gap between the tip and the upper edge.

As shown in FIG. 14A, the second protrusion V15 is in the same position as the chip thermistor in direction D1 when the opening region 70 is viewed from the external space SP2 side. However, the amount of protrusion of the second protrusion V15 is specified so that at least a portion of the chip thermistor is exposed. Specifically, the amount of protrusion of the second protrusion V15 is specified so that the tip of the second protrusion V15 does not exceed the upper surface of the chip thermistor. Note that, as an example here, the tip of the second protrusion V15 is located below the lower surface of the substrate 2, and the thermal detection element 30 is exposed between the pair of first protrusions V14 without being hidden behind the second protrusions V15.

The amount of protrusion of the second protrusion V15 is specified so that at least a portion of the chip thermistor is exposed in this manner, which further prevents heat from entering through the opening 7 and reduces the possibility of a person's finger or tool coming into contact with the chip thermistor.

As shown in FIG. 14B, each of the pair of first protrusions V14 also has a guide surface V2. Here, the cross-sectional shape of each of the pair of first protrusions V14 taken along the horizontal direction is an elongated ellipse along the radial direction of the housing 5, and has curved surfaces on both the left and right sides as guide surfaces V2. This further reduces the possibility that the shielding portion V1 will block the inflow of heat from the opening 7. In particular, the relatively small width dimension of each first protrusion V14 further reduces the possibility that the inflow of heat will be blocked.

On the other hand, the second protrusion V15 also has a guide surface V2, as shown in FIG. 14C. The second protrusion V15 is formed in a substantially triangular shape when viewed along the direction in which the pair of first protrusions V14 are aligned. In particular, the second protrusion V15 has a curved surface V150 that is concave and inclined in a substantially arc shape on the side of the internal space SP1 when viewed along the direction in which the pair of first protrusions V14 are aligned. This curved surface V150 also corresponds to the guide surface V2. When the hot air current collides with the guide surface V2, it can be guided toward the chip thermistor located above the second protrusion V15.

In this way, the detector 1H is provided with a shielding portion V1 having three protrusions, which makes it difficult for heat to flow in from the opening 7 to be impeded, while further reducing the possibility of a human finger or tool coming into contact with the chip thermistor.

The shielding portion V1 may have, for example, another first protrusion V14 between a pair of first protrusions V14. The other first protrusion V14 and the second protrusion V15 may protrude so that their tips face each other. In this case, as with the second protrusion V15, it is desirable that the protrusion amount of the other first protrusion V14 is specified so that at least a portion of the chip thermistor is exposed.

Next, we will explain variant 3 of this embodiment. Figure 16 shows detector 1I of variant 3. Detector 1I of variant 3 is an R-type heat detector, as an example.

The shielding portion V1 of the sensor 1I has a pair of first protrusions V16 formed integrally with the rear cover 52, similar to the pair of first protrusions V14 of the sensor 1H of the modified example 2. The pair of first protrusions V16 protrude from the rear cover 52 toward the front cover 51. The heat detection element 30 is disposed between the pair of first protrusions V16 in the direction D1 when the opening region 70 is viewed from the side of the external space SP2.

The shielding portion V1 of the sensor 1I further has a pair of second protrusions V17. Each of the pair of second protrusions V17 is formed integrally with the front cover 51, similar to the second protrusions V15 of the sensor 1H of the second modification example 2. The pair of second protrusions V17 protrude from the front cover 51 toward the rear cover 52. However, the pair of second protrusions V17 protrude such that their tips face the tips of the pair of first protrusions V16 in a one-to-one relationship. In other words, a gap is provided between each first protrusion V16 and the opposing second protrusion V17.

The shielding portion V1 of the detector 1I further includes a pillar V18. The pillar V18 is formed integrally with the front cover 51 of the housing 5, similar to the second pillar V13 of the detector 1G of the first modified example. The heat detection element 30 is located so as to overlap with the pillar V18 when the opening area 70 is viewed from the external space SP2 side. In other words, the heat detection element 30 is located in an invisible position, hidden behind the pillar V18.

When viewing the opening region 70 from the external space SP2 side, each of the pair of first projections V16 and the pillar V18 are disposed with a predetermined distance L4 between them in the direction D1. Here, as an example, the predetermined distance L4 is also a distance that is specified so that a test finger cannot be inserted.

In this way, the sensor 1I is provided with a shielding portion V1 having four protrusions and one pillar, which makes it difficult for heat to flow in from the opening 7, while further reducing the possibility of a human finger or tool coming into contact with the chip thermistor.

Although not shown in the figure, it is desirable that the shielding portion V1 of the sensor 1I also have an induction surface V2.

Next, we will explain variant 4 of this embodiment. Figures 17A and 17B show detector 1J of variant 4. Detector 1J of variant 4 is an R-type heat detector, as an example.

The shielding portion V1 of the detector 1J has only one pillar V19. The pillar V19 is formed integrally with the front cover 51 of the housing 5, similar to the second pillar V13 of the detector 1G of the first modified example. The heat detection element 30 is located so as to overlap with the pillar V19 when the opening area 70 is viewed from the external space SP2 side. In other words, the heat detection element 30 is located in an invisible position, hidden behind the pillar V19.

As shown in FIG. 17B, the pillar V19 has a guide surface V2. Here, the cross-sectional shape of the pillar V19 cut along the horizontal direction is a tapered shape that is pointed toward the internal space SP1, and this tapered surface corresponds to the guide surface V2. The cross-sectional shape of the pillar V19 is also semicircular on both the left and right sides, and these surfaces on both the left and right sides also correspond to the guide surface V2.

Thus, even though detector 1J has only one pillar V19, it is possible to reduce the possibility of a person's finger or tool coming into contact with the chip thermistor while making it difficult for heat to be impeded from the opening 7. If it is important to reduce the possibility of a person's finger or tool coming into contact with the chip thermistor, it is preferable that the number of protrusions or pillars on shielding portion V1 be two or more, as in detectors 1F to 1I.

(Embodiment 3)
The detector 1K according to this embodiment will be described below with reference to FIGS. 18A to 18C. Hereinafter, the components substantially similar to those in the first embodiment will be denoted by common reference numerals and will not be described as necessary. The detector 1K according to this embodiment is different from the detectors (1, 1A to 1E) according to the first embodiment (including the modified examples) in that the outer surface 53 has a first surface 531 formed in a tapered shape, as described later. The first surface 531 formed in a tapered shape in this embodiment may also be appropriately applied to the detectors (1, 1A to 1E) according to the first embodiment or the detectors (1F to 1J) according to the second embodiment. The detector 1K shown in FIGS. 18A to 18C is an R-type heat detector as an example. The detector 1K is a heat detector that does not include a smoke detector 4 and determines the occurrence of a fire or the like by detecting heat only, similar to the detector 1C according to the modified example 3 in the first embodiment. The detector 1K is also provided with a plurality of sets of shielding parts V1, similar to the detector 1H according to the modified example 2 in the second embodiment.

The opening 7 of the sensor 1K according to this embodiment has an inlet 7B, similar to the sensor 1C (see Figs. 8A and 8B) and the sensor 1D (see Figs. 9A and 9B) described in the first embodiment. That is, the opening 7 has an inlet 7B in addition to six side openings (horizontal holes) 7A. The inlet 7B is provided on the outer surface 53 (the underside of the front cover 51) of the housing 5 on the side opposite the structure X1 to which the sensor 1K is attached. Here, for example, the inlet 7B is provided in the center of the outer surface 53. The inlet 7B penetrates the front cover 51 in the thickness direction. The inlet 7B has a substantially circular opening.

In the detector 1K, as shown in FIG. 18B, a part of the substrate 2 is exposed from the inlet 7B. Specifically, the substrate 2 has a hole 25 penetrating in the thickness direction at its center. The hole 25 has a substantially circular opening. The hole 25 is arranged so as to roughly overlap with the inlet 7B. The substrate 2 has a pair of protrusions 26 that protrude toward each other at the opening edge of the hole 25. The tips of the pair of protrusions 26 are exposed from the inlet 7B. A thermal detection element 30 (chip thermistor) is also provided on the upper surface of each protrusion 26 of the substrate 2. In short, the detector 1K has a plurality of thermal detection elements 30 (six in the illustrated example) provided near the side opening (horizontal hole) 7A, as well as two thermal detection elements 30 near the inlet 7B. In addition, the substrate 2 has a substantially triangular through hole 31 in the vicinity of each thermal detection element 30 to prevent the heat in the thermal detection element 30 from being transferred through the substrate 2 and causing the temperature of the thermal detection element 30 to drop.

The opening 7 of the detector 1K has an inlet 7B, which allows it to detect the heat of the gas flowing in through the inlet 7B, thereby improving responsiveness in heat detection.

Here, the outer surface 53 of the sensor 1K of this embodiment has a first surface 531 around the inlet 7B and a second surface 532 located outside the first surface 531. In particular, as shown in FIG. 18C, the first surface 531 is tapered in a direction (upward) toward the structure X1 as it approaches the inlet 7B, at an inclination angle different from that of the second surface 532. Note that here, as an example, the outer surface 53 further has a third surface 533. The third surface 533 is located outside the first surface 531 and inside the second surface 532. When the outer surface 53 is viewed from the front, the first surface 531 to the third surface 533 are all donut-shaped. With regard to the radial dimensions of the outer surface 53, for example, the second surface 532 is the largest, the third surface 533 is next largest, and the first surface 531 is the smallest, but this is not particularly limited.

The inclination angle θ1 of the first surface 531 with respect to the horizontal plane is, for example, 23°. The inclination angle θ2 of the second surface 532 with respect to the horizontal plane is, for example, 0° to 1°. The inclination angle θ3 of the third surface 533 with respect to the horizontal plane is, for example, 8°.

In this way, in the detector 1K according to this embodiment, the outer surface 53 has a first surface 531 and a second surface 532, so that in the event of a fire, the inflow of heat into the inlet 7B can be further promoted (see the arrow in FIG. 18C). In particular, in the detector 1K, the outer surface 53, including the third surface 533, is inclined in two stages, so that the inflow of heat into the inlet 7B can be promoted more effectively.

However, regular inspections of this type of detector are required by law to check whether it is working properly (for example, once every six months). As shown in Figure 19A, an inspection worker 600 uses a specified (heating) tester 900 to perform a heating inspection of the thermal detection element 30 of detector 1K installed on structure X1 (the ceiling in the illustrated example).

The tester 900 has a heat source 910 such as a Hakukin hand warmer, a body 920 that is roughly cylindrical with an open top and houses the heat source 910 inside, and a support rod 930 that supports the body 920. During inspection, the body 920 is positioned so that it covers the base 511 and opening 7 of the front cover 51 of the detector 1K from below. If the heat detection element 30 and the like are normal, the detector 1K will receive a heat flow from the heat source 910 and perform the same operation as if it had detected a fire.

As explained in the first embodiment, the thermal detection element 30 is a chip thermistor mounted on the substrate 2, which allows the sensor (1, 1A-1K) to be made smaller (particularly thinner) as a whole. On the other hand, as the sensor becomes smaller, there is a possibility that the stability of the position of the tester 900 relative to the sensor may be lost during inspection.

Therefore, the housing 5 of the sensor 1K according to this embodiment has multiple (e.g., six) protrusions W1 (see Figures 18A and 18B; however, only four are shown in Figure 18A). The multiple protrusions W1 protrude from the edge (here, the upper edge) of the opening 7 in a direction (e.g., downward) away from the side of the structure X1 to which the sensor 1K is attached. The multiple protrusions W1 are arranged at equal intervals along the circumferential direction of the housing 5 when viewed, for example, from below.

The multiple protrusions W1 are configured to come into contact with the peripheral portion 901 (see FIG. 19B) of the tester 900 for performing a heating inspection of the thermal detection element 30 when the tester 900 is arranged to cover the housing 5. By providing multiple protrusions W1 in this manner, the tester 900 is stably arranged relative to the housing 5. In other words, the protrusions W1 are more likely to come into point contact with the peripheral portion 901, and rattling can be suppressed compared to when the protrusions W1 are not present and the housing 5 comes into surface contact with the peripheral portion 901.

Here, the multiple protrusions W1 protrude downward from the periphery of the lower end of the cylinder 510. The multiple protrusions W1 are located at the same position along the circumferential direction of the housing 5 so as to correspond one-to-one with the multiple crosspieces 512. Specifically, each protrusion W1 is formed integrally with a part (upper part) of the corresponding crosspiece 512. In other words, each protrusion W1 also functions as a part that reinforces the corresponding crosspiece 512. However, each protrusion W1 does not have to function as a reinforcing part of the crosspiece 512. Each protrusion W1 may be located at a position offset from the crosspiece 512 in the circumferential direction of the housing 5.

The number of protrusions W1 is not particularly limited and may be, for example, one. Even if there is only one protrusion W1, the housing 5 can be positioned more stably than when it is in surface contact with the peripheral portion 901 of the tester 900.

Figure 20 also shows a detector 1L which is a modification of the third embodiment. The detector 1L of this modification also has a first surface 531 in which the outer surface 53 is formed in a tapered shape. The detector 1L is a P-type heat detector, for example. In particular, like the detector 1G of the first modification of the second embodiment, the detector 1L has two sets of shielding portions V1 each having three columns (a pair of first columns V12 on the left and right and a second column V13 in the middle). In Figure 20, only one of the two sets of shielding portions V1 is shown, and the remaining set of shielding portions V1 is located on the back side.

The sensor 1L also has a plurality of (e.g., four) protrusions W1 (see FIG. 20: only three are shown) configured to come into contact with the peripheral portion 901 (see FIG. 19B) of the tester 900. At least one of the four protrusions W1 is integrally formed with a portion (upper portion) of the second pillar V13 in the middle of the shielding portion V1 so as to function as a portion that reinforces the second pillar V13. In other words, the four protrusions W1 of the sensor 1L are located at the same positions along the circumferential direction of the housing 5 as the two crosspieces 512 and the two second pillars V13 (including the second pillar V13 of the shielding portion V1 on the opposite side to the illustrated shielding portion V1) so as to correspond one-to-one to each of them.

(Embodiment 4)
The detector 1M according to this embodiment will be described below with reference to Figures 21A and 21B. Hereinafter, components substantially similar to those in the first embodiment will be denoted by common reference numerals and will not be described as necessary. The detector 1M shown in Figures 21A and 21B is an R-type heat detector as an example. The detector 1M is a heat detector that does not include a smoke detector 4 and determines the occurrence of a fire or the like by detecting heat only, similar to the detector 1C of the third modification in the first embodiment. The detector 1M is also provided with multiple sets of shielding parts V1 each having three pillars.

The detector 1M further includes a mounting base 100B for mounting the main body 100A on the structure X1 (the ceiling in the illustrated example). The mounting base 100B may also be applied as appropriate to the detectors of embodiment 1 (1, 1A-1E), embodiment 2 (1F-1J), or embodiment 3 (1K, 1L).

The mounting base 100B is generally formed in a flat cylindrical shape with an open bottom surface. The mounting base 100B is fixed to the surface of the structure X1 by screwing or the like. The structure X1 has holes for leading out the electric wires (power supply lines, signal lines, etc.) on its back side. The mounting base 100B has a through hole 103 (see FIG. 21B) in its bottom 106 for passing the electric wires leading out from the holes in the structure X1 toward the main body 100A.

Mounting base 100B also has an outer peripheral wall 104 and a flange portion 105 that protrudes outward from outer peripheral wall 104. Outer peripheral wall 104 is configured to fit into a recess formed by cylinder 510 and rear cover 52 (see FIG. 1) on the upper side of main body 100A. Although detailed explanation is omitted, for example, with outer peripheral wall 104 fitted into the recess of main body 100A, an engaged portion that engages with an engaging portion of rear cover 52 is provided on mounting base 100B by rotating clockwise in the axial direction. Main body 100A is fixed to mounting base 100B by engaging the engaging portion of rear cover 52 with the engaged portion.

As shown in FIG. 21A, when the main body 100A is fixed to the mounting base 100B, the outer circumferential surface of the flange 105 and the outer circumferential surface of the cylindrical body 510 of the sensor 1M are substantially flush with each other, so that the sensor 1M can be provided as a sensor with a good appearance.

The above-mentioned mounting base 100B is a type of base unit that directly mounts the sensor 1M on the surface of the structure X1. In contrast, as a modification of this embodiment, instead of the mounting base 100B, the sensor 1M may be provided with an embedded base 100C, as shown in Figures 22A and 22B. The embedded base 100C is a type of base unit that embeds the sensor 1M in the structure X1.

The embedded base 100C has a base body 107 that is inserted into an embedding hole in the structure X1, and a decorative portion 108 that is formed integrally with the base body 107.

The base body 107 is formed in a flat cylindrical shape with an open bottom surface. The embedded base 100C further has a mounting bracket (first mounting bracket T1 or second mounting bracket T2 described below) for fixing the embedded base 100C to the structure X1 when inserted into the hole of the structure X1. The base body 107 has a through hole 110 (see FIG. 22B) in the bottom 109 for passing the electric wire on the back side of the structure X1 toward the main body 100A.

The base body 107 has a recess 111 with an inner diameter slightly larger than the outer diameter of the body 100A. In other words, the body 100A can be accommodated in the recess 111. Here, the recess 111 has a depth such that approximately half of the cylindrical body 510 in the vertical direction fits within the recess 111.

The decorative portion 108 protrudes outward from the lower end of the base body 107 in a flange-like shape. When the base body 107 is inserted into the hole in the structure X1, the decorative portion 108 is exposed and positioned below the surface of the structure X1.

Although a detailed description is omitted, for example, when the main body 100A is fitted into the recess 111 of the base main body 107 and rotated clockwise in the axial direction, an engaged portion that engages with the engaging portion of the rear cover 52 is provided on the embedded base 100C. The main body 100A is fixed to the embedded base 100C by the engaging portion of the rear cover 52 engaging with the engaged portion.

As shown in FIG. 22A, when the main body 100A is fixed to the embedded base 100C, the sensor 1M can be provided as a sensor with a good appearance because the amount of protrusion from the surface of the structure X1 can be reduced.

Here, a method of attaching the embedded base 100C to the structure X1 using a pair of first mounting brackets T1 will be described with reference to FIG. 23A. The embedded base 100C has a pair of first mounting brackets T1. For ease of explanation, FIG. 23A shows only the structure X1 in cross section. Each first mounting bracket T1 has a fixing screw T11 and a fixing piece T12 in the form of a partially bent leaf spring. The fixing piece T12 has a screw hole into which the fixing screw T11 is screwed. The fixing piece T12 is provisionally fixed to the fixing screw T11 on the upper side of the base body 107 with the fixing screw T11 inserted from below into a through hole in the bottom 109 of the base body 107. In other words, the bottom 109 is sandwiched between the flat portion T120 of the fixing piece T12 and the head of the fixing screw T11.

When attaching the embedded base 100C to the structure X1, first loosen each of the fixing screws T11 with a tool such as a screwdriver to release the above-mentioned pinched state. In this state, each of the fixing pieces T12 can be tilted inward together with the fixing screws T11 (see the imaginary lines in FIG. 23A). The fixing pieces T12 are tilted inward, and while maintaining this state, the base body 107 is inserted into the hole X11 of the structure X1. Then, by tightening each of the fixing screws T11 with a tool such as a screwdriver, the fixing pieces T12 fall outward with the flat part T120 in contact with the base body 107 as a fulcrum, and the tip T121 (point of action) comes into contact with the back surface of the structure X1. Then, by further tightening each of the fixing screws T11, the structure X1 is pinched in the vertical direction between the tip T121 of each of the fixing pieces T12 and the decorative part 108, and as a result, the embedded base 100C is fixed to the structure X1.

Next, a method of attaching the embedded base 100C to the structure X1 using a pair of second mounting brackets T2 will be described with reference to FIG. 23B. The embedded base 100C has a pair of second mounting brackets T2. For ease of explanation, FIG. 23B shows only the structure X1 in cross section. Each second mounting bracket T2 has a fixing screw T21 and a flat rectangular plate-shaped fixing piece T22. The fixing piece T22 has a screw hole into which the fixing screw T21 is screwed. The fixing piece T22 is provisionally fixed to the fixing screw T21 on the upper side of the decorative part 108 with the fixing screw T21 inserted from below into a through hole in the decorative part 108.

When attaching the embedded base 100C to the structure X1, first loosen each of the fixing screws T21 with a tool such as a screwdriver and rotate them so that the tips of the fixing pieces T22 face inward. While maintaining this state, insert the base body 107 into the hole X11 of the structure X1. Then, by tightening each of the fixing screws T21 with a tool such as a screwdriver, the tips of the fixing pieces T22 face outward, and the fixing pieces T22 further descend toward the back surface of the structure X1 and generally come into surface contact. Then, by further tightening each of the fixing screws T21, the structure X1 is sandwiched in the vertical direction between each of the fixing pieces T22 and the decorative portion 108, and as a result, the embedded base 100C is fixed to the structure X1.

The first mounting bracket T1 and the second mounting bracket T2 described above are merely examples, and the mounting brackets for fixing the embedded base 100C to the structure X1 are not limited to these. The mounting method described above is also merely an example, and is not limited to these.

(4) Summary As described above, the detector (1, 1A to 1M) according to the first aspect includes a substrate (2), a heat detection element (30), and a housing (5). The housing (5) houses the substrate (2). The housing (5) has a flow path (6) provided in its internal space (SP1) through which gas flows, and an opening (7) connecting the flow path (6) to the external space (SP2) of the housing (5). The heat detection element (30) is a chip thermistor mounted on the substrate (2) and detects the heat of the gas flowing in from the opening (7). According to the first aspect, since the heat detection element (30) is a chip thermistor mounted on the substrate (2), the detector (1, 1A to 1M) can be made smaller as a whole.

Regarding the detector (1, 1A-1M) according to the second aspect, in the first aspect, it is preferable that at least a portion of the surface (e.g., first surface 21) of the substrate (2) is exposed to the flow path (6). According to the second aspect, the possibility that the thermal detection element (30) is exposed to the gas flowing through the flow path (6) can be increased, so that the thermal detection performance can be improved while the detector can be made smaller.

Regarding the detector (1, 1A-1M) according to the third aspect, in the first or second aspect, it is preferable that the chip thermistor is arranged so as to be contained within the opening area (70) when the opening area (70) of the opening (7) is viewed from the external space (SP2) side. According to the third aspect, it is possible to further increase the possibility that the heat detection element (30) is exposed to the gas flowing through the flow path (6), thereby enabling miniaturization while further improving heat detection performance.

Regarding the sensor (1, 1A-1M) according to the fourth aspect, in the third aspect, the chip thermistor is preferably located in the following position. That is, when the opening area (70) is viewed from the external space (SP2) side, the chip thermistor is preferably located within the opening area (70) at the center of the opening area (70) in a direction perpendicular to the surface (e.g., first surface 21) of the substrate (2). According to the fourth aspect, the possibility that the thermal detection element (30) is exposed to the gas flowing through the flow path (6) can be further increased compared to, for example, a case in which the chip thermistor is located toward one end of the opening area (70) in the above direction.

Regarding the sensor (1, 1A-1M) according to the fifth aspect, in any one of the first to fourth aspects, the flow path (6) includes a first path (61) on the side of the opening (7) and a second path (62) connected to the first path (61) and on the side of the center of the internal space (SP1). The chip thermistor is preferably located within the first path (61). According to the fifth aspect, the responsiveness in terms of heat detection can be improved, for example, compared to a case in which the chip thermistor is located within the second path (62).

Regarding the sensor (1, 1A-1M) according to the sixth aspect, in any one of the first to fifth aspects, the flow path (6) includes a first path (61) on the side of the opening (7) and a second path (62) connected to the first path (61) and on the side of the center of the internal space (SP1). It is preferable that the opening cross-sectional area of the first path (61) is smaller than the opening cross-sectional area of the second path (62). According to the sixth aspect, the gas that has entered the flow path (6) through the opening (7) can be promoted to flow from the first path (61) toward the second path (62).

Regarding the sensor (1, 1A-1M) according to the seventh aspect, in the sixth aspect, it is preferable that the housing (5) has an installation surface (55) facing the structure (X1) to which the sensor (1, 1A-1M) is attached. It is preferable that the second path (62) widens in a direction approaching the installation surface (55) as it moves from the first path (61) toward the central portion. According to the seventh aspect, it is possible to more effectively generate an airflow from the first path (61) toward the second path (62).

The detector (1, 1A-1M) according to the eighth aspect is preferably any one of the first to seventh aspects, further comprising a smoke detector (4) that is disposed in the center of the internal space (SP1) and detects smoke. According to the eighth aspect, since the detector detects not only heat but also smoke, it is possible to improve the fire detection performance while miniaturizing the detector (1, 1A-1M) as a whole.

Regarding the detector (1, 1A-1M) according to the ninth aspect, in the eighth aspect, it is preferable that the smoke detection unit (4) is arranged on the same plane as the surface (e.g., the first surface 21) of the substrate (2) on which the chip thermistor is mounted. According to the ninth aspect, it is possible to further improve the fire detection performance while miniaturizing the detector (1, 1A-1M) as a whole.

Regarding the detector (1, 1A-1M) according to the tenth aspect, in the eighth or ninth aspect, it is preferable that the housing (5) has an installation surface (55) facing the structure (X1) to which the detector (1, 1A-1M) is attached. It is preferable that the smoke detector (4) is disposed on the surface of the substrate (2) that is closer to the installation surface (55) than the surface (e.g., the first surface 21) or the surface opposite the surface (e.g., the second surface 22). According to the tenth aspect, it is possible to achieve further miniaturization compared to, for example, a case in which the smoke detector (4) is disposed on the surface farther from the installation surface (55).

Regarding the detector (1, 1A-1M) according to the eleventh aspect, in any one of the eighth to tenth aspects, it is preferable that the housing (5) has one or more walls (control plates 522) in the internal space (SP1). It is preferable that the one or more walls (control plates 522) guide gas to the heat detection element (30) or the smoke detection section (4). According to the eleventh aspect, it is possible to further improve the fire detection performance.

Regarding the detector (1, 1A-1M) according to the twelfth aspect, in any one of the eighth to eleventh aspects, it is preferable that the housing (5) has an installation surface (55) facing the structure (X1) to which the detector (1, 1A-1M) is attached. The smoke detection unit (4) has an optical element (41) that emits light, a light receiving element (42) that receives the light emitted from the optical element (41), and a labyrinth portion (43). Within the labyrinth portion (43), the optical element (41) and the light receiving element (42) are arranged so as not to face each other. In the thickness direction (vertical direction) of the substrate (2), it is preferable that the center (P1) of the internal space of the labyrinth portion (43) is between the chip thermistor and the installation surface (55). According to the twelfth aspect, in a detector (1, 1A to 1M) that detects not only heat but also smoke, it is possible to further improve the fire detection performance while reducing the overall size of the detector (1, 1A to 1M).

Regarding the sensor (1, 1A-1M) according to the thirteenth aspect, in any one of the first to twelfth aspects, the chip thermistor is preferably arranged so as to be contained within the opening area (70) when the opening area (70) of the opening (7) is viewed from the external space (SP2) side. The sensor (1, 1A-1M) preferably further includes a shielding portion (V1) that blocks a part of the opening area (70) on the external space (SP2) side of the chip thermistor. According to the thirteenth aspect, the provision of the shielding portion (V1) makes it difficult to impede the inflow of heat from the opening (7), while reducing the possibility of, for example, a person's finger or a tool unintentionally touching the chip thermistor.

Regarding the detector (1, 1A-1M) according to the 14th aspect, in the 13th aspect, it is preferable that the shielding portion (V1) has a guide surface (V2) that guides the airflow from the external space (SP2) toward the chip thermistor. According to the 14th aspect, the possibility that the shielding portion (V1) will block the inflow of heat from the opening (7) can be further reduced.

Regarding the sensor (1, 1A-1M) according to the 15th aspect, in the 13th or 14th aspect, it is preferable that the housing (5) has a first cover (for example, one of the front cover 51 and the back cover 52) and a second cover (the other). The first cover covers the substrate (2) from one direction in the thickness direction of the substrate (2). The second cover covers the substrate (2) from the opposite direction to the one direction in the thickness direction. It is preferable that the shielding portion (V1) has a first protrusion (V14, V16) protruding from the first cover toward the second cover, and a second protrusion (V15, V17) protruding from the second cover toward the first cover. According to the 15th aspect, it is possible to further reduce the possibility of a human finger or a tool coming into contact with the chip thermistor while making it difficult for heat to flow in from the opening (7).

Regarding the sensor (1, 1A-1M) according to the 16th aspect, in the 15th aspect, it is preferable that the first protrusion (V14) is disposed as follows. That is, when the opening area (70) is viewed from the external space (SP2) side, the first protrusion (V14) is preferably disposed offset from the second protrusion (V15) in a direction perpendicular to the arrangement direction of the first cover and the second cover. According to the 16th aspect, it is possible to further reduce the possibility that the shielding portion (V1) will prevent heat from entering from the opening (7).

Regarding the sensor (1, 1A-1M) according to the 17th aspect, in the 15th aspect, it is preferable that the first protrusion (V16) and the second protrusion (V17) protrude so that their tips face each other. According to the 17th aspect, the possibility of a person's finger or a tool coming into contact with the chip thermistor can be further reduced.

Regarding the detector (1, 1A-1M) according to the 18th aspect, in any one of the 15th to 17th aspects, at least one of the first protrusion (V14, V16) and the second protrusion (V15, V17) (here, the second protrusion V15) is preferably as follows. That is, when the opening region (70) is viewed from the external space (SP2), the at least one is preferably in the same position as the chip thermistor in a direction perpendicular to the arrangement direction of the first cover and the second cover. Furthermore, when the opening region (70) is viewed from the external space (SP2), the protrusion amount of the at least one is preferably specified so that at least a part of the chip thermistor is exposed. According to the 18th aspect, it is possible to further reduce the possibility of a person's finger or a tool coming into contact with the chip thermistor while making it difficult to impede the inflow of heat from the opening (7).

Regarding the detector (1, 1A-1M) according to the 19th aspect, in any one of the first to 18th aspects, it is preferable that the opening (7) has an inlet (7B). The inlet (7B) is provided on the outer surface (53) of the housing (5) on the opposite side to the structure (X1) to which the detector (1, 1A-1M) is attached. According to the 19th aspect, the heat of the gas flowing in from the inlet (7B) can be detected, thereby improving the responsiveness in heat detection.

Regarding the detector (1, 1A-1M) according to the twentieth aspect, in the 19th aspect, it is preferable that the outer surface (53) has a first surface (531) around the inlet (7B) and a second surface (532) located outside the first surface (531). It is preferable that the first surface (531) is tapered at an inclination angle different from that of the second surface (532) in a direction approaching the structure (X1) as it approaches the inlet (7B). According to the twentieth aspect, the flow of heat into the inlet (7B) can be further promoted.

Regarding the detector (1, 1A-1M) according to the 21st aspect, in any one of the first to 20th aspects, the housing (5) preferably has one or more convex parts (W1). The one or more convex parts (W1) protrude from the edge of the opening (7) in a direction away from the side of the structure (X1) to which the detector (1, 1A-1M) is attached. The one or more convex parts (W1) are preferably configured to contact the peripheral part (901) of the tester (900) for performing a heating inspection of the thermal detection element (30) when the tester (900) is arranged to cover the housing (5). According to the 21st aspect, the provision of the convex part (W1) allows the tester (900) to be stably arranged relative to the housing (5). That is, the convex part (W1) is more likely to come into point contact with the peripheral part (901), and rattling can be suppressed compared to surface contact.

The configurations relating to the second to twelfth aspects are not essential components of the detectors (1, 1A to 1E) and may be omitted as appropriate.

REFERENCE SIGNS LIST 1, 1A to 1M Detector 2 Substrate 30 Heat detection element 4 Smoke detection section 41 Optical element 42 Light receiving element 43 Labyrinth section 5 Housing 51 Front cover (second cover)
52 Back cover (first cover)
53 Outer surface 531 First surface 532 Second surface 55 Installation surface 522 Control panel (wall)
6 Flow path 61 First path 62 Second path 7 Opening 7B Inlet 70 Opening area P1 Center SP1 Internal space SP2 External space V1 Shielding portion V14, V16 First projection V15, V17 Second projection V2 Guide surface W1 Convex portion X1 Structure 900 Tester 901 Periphery

Claims (8)

A substrate;
A thermal detection element;
A housing that houses the substrate;
Equipped with
The housing includes:
a flow path provided in the internal space through which a gas flows;
An opening that connects the flow path and an external space of the housing;
A smoke detection unit disposed in the internal space and configured to detect smoke;
having
the thermal detection element is a chip thermistor mounted on the substrate and configured to detect the heat of the gas flowing in through the opening.
sensor. The smoke detector is disposed on the same plane as the surface of the substrate on which the chip thermistor is mounted.
2. The detector of claim 1. The smoke detection unit is disposed on a plane side different from the surface of the substrate on which the chip thermistor is mounted.
2. The detector of claim 1. the housing has an installation surface facing a structure to which the sensor is attached,
The smoke detection unit is disposed on a surface of the substrate and a surface opposite to the surface, the surface being closer to the installation surface.
A detector according to any one of claims 1 to 3. The housing has one or more walls in the internal space that guide the gas to the heat detection element or the smoke detection unit.
A detector according to any one of claims 1 to 4. the housing has an installation surface facing a structure to which the sensor is attached,
The smoke detection unit is
an optical element that emits light;
a light receiving element that receives the light emitted from the optical element;
a labyrinth portion in which the optical element and the light receiving element are arranged so as not to face each other;
having
the center of the internal space of the labyrinth portion in the thickness direction of the substrate is between the chip thermistor and the installation surface;
A detector according to any one of claims 1 to 5. the housing has an installation surface facing a structure to which the sensor is attached,
The substrate has a first surface facing the installation surface and a second surface opposite to the first surface,
the chip thermistor is mounted on the first surface or the second surface which is a mounting surface of the substrate,
the chip thermistor has a rectangular shape when viewed from a direction perpendicular to the mounting surface of the substrate, and has one surface facing the substrate in a thickness direction of the substrate.
A detector according to any one of claims 1 to 6. An automatic fire alarm system comprising a detector according to any one of claims 1 to 7 and a receiver that communicates with the detector.

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