Detectors and automatic fire alarm systems

Abstract

To achieve miniaturization.SOLUTION: A sensor 1 includes a substrate 2, heat detection elements 30, and a housing 5. The housing 5 stores the substrate 2. The housing 5 includes: a flow channel 6 arranged in an internal space SP1 to allow gas to flow therethrough; and an opening part 7 for connecting the flow channel 6 to an outer space SP2 of the housing 5. The heat detection element 30 is a chip thermistor mounted on the substrate 2 so as to detect heat of the gas flow-in from the opening part 7.SELECTED DRAWING: Figure 1

Description

[[Technical Field]]

[0001] The present disclosure generally relates to a sensor and an automatic fire alarm system, and more particularly to a sensor that senses heat generated by, for example, a fire, and an automatic fire alarm system including the sensor. [[Background Art]]

[0002] As a conventional example, the heat-smoke combined sensor described in Patent Document 1 is exemplified. This sensor includes heat sensing means for sensing heat, and a smoke sensing unit for sensing smoke flowing into a dark box. The heat sensing means includes a lead wire connected to a circuit board and protruding upward from the circuit board, and a heat sensitive element such as a thermistor provided at an upper end of the lead wire. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Application Publication No. 2012-014330 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] In the sensor of Patent Document 1, since the heat sensitive element is provided at the upper end of the lead wire, it may be difficult to reduce the size (particularly, reduce the thickness) of the entire sensor depending on the length of the lead wire.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a sensor capable of reducing size, and an automatic fire alarm system. [[Means for Solving the Problem]]

[0006] A sensor according to an aspect of the present disclosure includes a substrate, a heat detection element, and a housing. The housing accommodates the substrate. The substrate has a main body and an extension that extends from the edge of the main body in a direction away from the center of the main body. The thermal sensing element is arranged on the extension. An automatic fire alarm system according to one aspect of this disclosure comprises the above-mentioned detector and a receiver that communicates with the detector. [Effects of the Invention]

[0007] According to this disclosure, there is the advantage that miniaturization can be achieved. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view of a sensor according to Embodiment 1. [Figure 2] Figure 2 is a perspective view of the same sensor as above, seen from below. [Figure 3] Figure 3A is a partially transparent plan view of the same sensor. Figure 3B is an enlarged plan view of the main part of Figure 3A. [Figure 4] Figure 4 is a schematic block diagram of the above-mentioned sensor. [Figure 5] Figure 5 is a magnified view of the opening in the above-mentioned sensor, seen from the front. [Figure 6] Figure 6 is a schematic cross-sectional view of Modification 1 of the same sensor. [Figure 7] Figure 7 is a schematic cross-sectional view of Modification 2 of the same sensor. [Figure 8] Figure 8A is a perspective view from below of Modification 3 of the same sensor. Figure 8B is a partially perspectived plan view of Modification 3. [Figure 9] Figure 9A is a perspective view from below of Modification 4 of the same sensor. Figure 9B is a partially perspectived plan view of Modification 4. [Figure 10] Figure 10A is a perspective view from below of Modification 5 of the same sensor. Figure 10B is a partially perspectived plan view of Modification 5. [Figure 11] Figure 11 is a perspective view from below of another modified example of the same sensor. [Figure 12]Figure 12A is a side view of the main part of the sensor according to Embodiment 2. Figure 12B is a cross-sectional view of the main part of the same sensor, cut along the horizontal direction. [Figure 13] Figure 13A is a side view of the main part of Modification 1 of the above sensor. Figure 13B is a cross-sectional view of the main part of Modification 1, cut along the horizontal direction. Figure 13C is a cross-sectional view of the main part of another example of Modification 1, cut along the horizontal direction. [Figure 14] Figure 14A is a side view of the main part of Modification 2 of the same sensor. Figure 14B is a cross-sectional view of the main part of Modification 2, cut along the horizontal direction. Figure 14C is a perspective view of the main part of Modification 2, the same sensor. [Figure 15] Figure 15 is an exploded perspective view of the main part of the modified example 2 shown above. [Figure 16] Figure 16 is a side view of the main part of Modification 3 of the same sensor. [Figure 17] Figure 17A is a side view of the main part of Modification 4 of the same sensor. Figure 17B is a cross-sectional view of the main part of Modification 4, cut along the horizontal direction. [Figure 18] Figure 18A is a perspective view of the detector according to Embodiment 3, seen from below. Figure 18B is a partially transparent plan view of the same detector. Figure 18C is a cross-sectional view of the main part of the same detector, cut vertically along the inlet. [Figure 19] Figure 19A shows a heating test being performed on the same sensor installed on a structure using a test device. Figure 19B is a schematic cross-sectional view of the test device with the sensor covered by the test device. [Figure 20] Figure 20 is a perspective view from below of a modified example of the same sensor. [Figure 21] Figure 21A is a perspective view showing the main body of the sensor according to Embodiment 4 directly attached to a structure using a mounting base. Figure 21B is an exploded perspective view of the main body of the sensor and the mounting base shown above. [Figure 22]FIG. 22A is a perspective view showing a state where the main body of the aforementioned detector is embedded and installed in a structure using an embedded base. FIG. 22B is an exploded perspective view of the main body of the aforementioned detector and the aforementioned embedded base. [Figure 23] FIG. 23A is a partial cross-sectional view schematically showing a state where the aforementioned embedded base is attached to a structure using a first attachment fitting. FIG. 23B is a partial cross-sectional view schematically showing a state where the aforementioned embedded base is attached to the structure using a second attachment fitting. MODES FOR CARRYING OUT THE INVENTION

[0009] (Embodiment 1) (1) Outline Each drawing described in the following embodiments is a schematic diagram, and the ratio of the size and thickness of each component in each drawing does not necessarily reflect the actual dimensional ratio.

[0010] The detector 1 of the present embodiment is, for example, a fire detector, and includes a heat detection element 30 that detects heat generated by a fire or the like. In other words, the detector 1 is a detector having at least a function of detecting heat. Hereinafter, as an example, it is assumed that the detector 1 is a so-called combined fire detector further including a smoke detection unit 4 (see FIG. 1) (see FIGS. 1 to 5). The detector 1 may include a detection unit that detects flame, gas leakage, generation of CO (carbon monoxide) due to incomplete combustion, or the like instead of or in addition to the smoke detection unit 4.

[0011] As shown in FIG. 2, the detector 1 is installed on a structure X1 (a ceiling in the illustrated example), which is a construction material such as a ceiling or a wall of a building, for example.

[0012] As shown in FIGS. 1 to 3A, the detector 1 includes a substrate 2, one or more heat detection elements 30, and a housing 5. Here, as an example, the detector 1 includes four heat detection elements 30.

[0013] The housing 5 houses the circuit board 2. As shown in Figure 1, the housing 5 has a flow path 6 through which gas flows in its internal space SP1, and an opening 7 connecting the flow path 6 to the external space SP2 of the housing 5. In Figure 1, the flow path 6 is schematically shown with an arrow line to make it easier to understand the gas flow, but the air gap around the smoke detection unit 4 in the internal space SP1 can roughly correspond to the flow path 6. Also, as an example, the housing 5 has six openings 7 (only three are shown in Figure 2).

[0014] In this embodiment, the thermal sensing element 30 is a chip thermistor mounted on the substrate 2, as shown in Figure 1, which detects the heat of the gas flowing in through the opening 7.

[0015] With this configuration, since the heat sensing element 30 is a chip thermistor mounted on the substrate 2, the overall size (especially the thickness) of the sensor 1 can be reduced compared to, for example, the configuration in Patent Document 1 in which the heat sensing element is provided at the upper end of the lead wire.

[0016] (2) Details (2.1) Overall structure The overall configuration of the detector 1 according to this embodiment will be described in detail below. As mentioned above, the detector 1 is a so-called combined fire detector that detects heat and smoke.

[0017] In the following explanation, we assume that sensor 1 is installed on the ceiling surface (one side of structure X1), as shown in the example in Figure 2. Therefore, the up / down, left / right, and front / back directions of sensor 1 will be defined and explained using the up / down, left / right, and front / back arrows shown in Figure 2. These arrows are included solely for explanatory purposes and do not represent any actual physical dimensions. Furthermore, these directions are not intended to limit the direction in which sensor 1 can be used.

[0018] The detector 1 includes a heat detection unit 3 having the four heat detection elements 30 described above. In addition to the circuit board 2, heat detection unit 3, smoke detection unit 4, and housing 5, the detector 1 further includes a display unit 8 and a control unit 9 (see Figure 4). The detector 1 also includes a mounting part 10 for attaching to the structure X1 (see Figure 1). In Figure 1, the mounting structure on the structure X1 side to which the mounting part 10 is fixed (for example, a disc-shaped mounting base) is not shown. The detector 1 is detachably attached to the mounting base fixed to the structure X1.

[0019] The detector 1 includes a communication unit 11 that, when it detects a fire, transmits a signal to an external alarm device (not shown) to indicate the occurrence of a fire, and also receives signals from the alarm device.

[0020] The sensor 1 may be powered by a commercial power supply, or by a battery located inside the housing 5.

[0021] (2.2) Enclosure The housing 5 houses the circuit 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 inside. The housing 5 also supports the display unit 8 so that one side of the guide unit 82 is exposed to the outside (see Figure 2).

[0022] The housing 5 is made of synthetic resin, for example, flame-retardant ABS resin. The housing 5 is formed as a whole in a cylindrical shape that is flattened in the vertical direction. As shown in Figure 1, the housing 5 has a cylindrical front cover 51 with one side (the top surface in the illustrated example) open, and a disc-shaped back cover 52. The housing 5 has an installation surface 55 (see Figure 1) that faces the structure X1 to which the sensor 1 is attached. Here, one side (the 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 its open side.

[0023] Furthermore, as described above, the housing 5 has a flow path 6 through which gas flows in its internal space SP1, and six side openings (lateral holes) 7A that connect the flow path 6 to the external space SP2. In other words, the openings 7 have side openings 7A. The number of openings 7 is not particularly limited, but it is preferable to have two or more considering the entry and exit of gas to and from the housing 5.

[0024] Here, six openings 7 (six side openings 7A) are provided in the front cover 51. Specifically, as shown in Figures 1 and 2, the front cover 51 is composed of a flattened cylindrical body 510 with open upper and lower ends, a disc-shaped base 511 located below the cylindrical body 510, and a plurality of (for example, six) crossbars 512 connecting the cylindrical body 510 and the base 511. The cylindrical body 510, the base 511, and the six crossbars 512 are formed as a single unit. The six crossbars 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 cylindrical body 510. The six crossbars 512 maintain a specified distance between the cylindrical body 510 and the base 511. The six openings 7 are arranged at approximately equal intervals along the circumferential direction on the peripheral wall of the front cover 51 thus constructed.

[0025] 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.

[0026] The front cover 51 has a positioning structure on the upper surface side of the base 511 for positioning the substrate 2. As an example of the positioning structure, a positioning recess may be provided on the upper surface side of the base 511, and a claw piece protruding from the substrate 2 may be fitted into the recess. As shown in Figure 3A, the base 511 has a diameter slightly larger than the diameter of the substrate 2.

[0027] Furthermore, the front cover 51 has a pair of holes 513 (see Figure 3A) in its base 511 for exposing one side (bottom surface) of the guide portion 82 of the display unit 8 to the external space SP2.

[0028] The pair of holes 513 are located near the periphery of the base 511 when viewed from below. The pair of holes 513 are arranged to be equally spaced in the circumferential direction of the base 511. In other words, the pair of holes 513 are arranged such that an imaginary line connecting them passes through the center of the base 511. The direction in which the pair of holes 513 are aligned corresponds to the front-to-back direction in this disclosure.

[0029] 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 out to the outside of the housing 5 via the pair of guide portions 82.

[0030] The back cover 52 has multiple insertion holes 520 into which multiple (e.g., four) connecting pieces 101 of the mounting portion 10 fixed to the substrate 2 are inserted (see Figure 1). The multiple connecting pieces 101 are electrically connected to the circuit module provided on the substrate 2. The multiple connecting pieces 101 are inserted so that their tips protrude sufficiently from the back side (mounting surface 55 side) of the back cover 52. The multiple connecting pieces 101 can be mechanically and electrically connected to the contact portion of a mounting base (not shown) fixed to the structure X1. In short, the mounting portion 10 is not merely a mechanical connection to the mounting base, but also an electrical connection to the wires (power supply lines and signal lines) on the back side of the structure X1, and also serves to stably position the substrate 2 relative to the back cover 52. This positioning includes not only the radial positioning of the substrate 2, but also the vertical positioning of the substrate 2.

[0031] Furthermore, the back cover 52 has a recessed area 521 (see Figure 1) on one side (bottom surface) facing the substrate 2 for accommodating the upper part of the smoke detection unit 4 mounted on the substrate 2. In other words, the smoke detection unit 4 is stably positioned by the recessed area 521.

[0032] Furthermore, the back cover 52 has a plurality of control plates (walls) 522 (see Figure 3A: four in the illustrated example) on one side (bottom surface) facing the substrate 2, which control the flow of gas in the flow path 6. Each control plate 522 is formed in a substantially arc shape when viewed from the substrate 2 side. Each control plate 522 protrudes in a direction toward the base 511 of the front cover 51 (downward). The four control plates 522 are arranged at substantially equal intervals along the circumferential direction of the back cover 52 near the peripheral edge of the back cover 52 when viewed from the substrate 2 side. The four control plates 522 control (induce) 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.

[0033] (2.3) Substrate The circuit board 2 is a printed circuit board. The circuit 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 illuminates the light source 81 of the display unit 8 and the optical element 41 of the smoke detection unit 4, as well as a power supply circuit that generates operating power for various circuits using power supplied from a commercial power source or the like.

[0034] As shown in Figure 3A, the substrate 2 is formed in a roughly circular shape overall. Figure 3A is a plan view of the sensor 1 from below, with a portion (substrate 2, control plate 522, and smoke detection unit 4) transparent.

[0035] In this embodiment, at least four heat sensing elements 30 of the heat sensing 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 Figure 1). Here, 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 section 43 (described later) of the smoke detection unit 4 has engaging claws on the lower surface of its bottom, and is fixed by engaging these engaging claws with engaging holes 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.

[0036] The control unit 9 and the multiple electronic components constituting 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 constituting the circuit module do not have to be mounted only on the substrate 2; for example, another mounting substrate may be placed around the substrate 2, and some or all of them may be mounted on that mounting substrate.

[0037] Hereafter, the side opposite the first surface 21 (top surface) of the substrate 2 may be referred to as the second surface 22 (bottom surface). In Figure 3A, the substrate 2 is 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 on the back side of the second surface 22, but for the sake of explanation, these are also shown transparently in Figure 3A. In particular, in Figure 3A, the optical element 41 and light receiving element 42, which are located within the labyrinth section 43 of the smoke detection unit 4, are simplified and shown as dots.

[0038] 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 located on the surface of the substrate 2 that is closer to the installation surface 55.

[0039] The structure of the substrate 2 will now be described in detail. As shown in Figure 3A, the substrate 2 has a circular main body 200 and a plurality of extensions (eight in the illustrated example) that extend away from the center of the main body 200 at its edge. Hereinafter, the eight extensions will be referred to as a pair of first extensions 201, a pair of second extensions 202, a pair of third extensions 203, and a pair of fourth extensions 204.

[0040] The smoke detection unit 4 is located on the upper surface of the main body 200. Meanwhile, the four heat detection elements 30 and the two light sources 81 are located in the six extensions (201, 202, and 203), respectively.

[0041] A pair of first extensions 201 extend from the left and right edges of the main body 200, respectively, in directions away from each other. A corresponding connecting piece 101 is positioned on the upper surface of each first extension 201. Each first extension 201 also has a narrower small piece Y1 at its tip. A corresponding heat sensing element 30 is positioned on the upper surface of each small piece Y1.

[0042] A pair of second extensions 202 extend from the front and rear edges of the main body 200, each in a direction away from the others. The extension amount of the second extensions 202 is less than that of the other extensions. A corresponding light source 81 is positioned on the upper surface of each second extension 202.

[0043] The pair of third extensions 203 extend away from each other from positions slightly offset counterclockwise from the front and rear edges of the main body 200 when viewed from below the substrate 2. Specifically, the front third extension 203 is positioned to the left of the front second extension 202, and the rear third extension 203 is positioned to the right of the rear second extension 202. Each third extension 203, like the first extension 201, has a narrower small piece Y1 at its tip. A corresponding heat sensing element 30 is positioned on the upper surface of each small piece Y1.

[0044] The pair of fourth extensions 204 extend away from each other from positions slightly offset in a clockwise direction from the front and rear edges of the main body 200 when viewed from the underside of the substrate 2. Specifically, the front fourth extension 204 is positioned to the right of the front second extension 202, and the rear fourth extension 204 is positioned to the left of the rear second extension 202. A corresponding connecting piece 101 is positioned on the upper surface of each fourth extension 204.

[0045] In short, substrate 2 has a shape that is symmetrical twice, for example, by rotating it 180 degrees around its center.

[0046] Incidentally, each of the pair of first extensions 201 and the pair of third extensions 203, on which the four heat sensing elements 30 are arranged, is provided with a through-hole 31 (see Figure 3B) having a rectangular opening. Figure 3B is, as an example, an enlarged view of the circular area enclosed by the dotted line (imaginary line) in Figure 3A. The through-hole 31 is located inside the heat sensing elements 30 (towards the center of the internal space SP1). The heat sensing elements 30 and the through-hole 31 are arranged adjacent to each other. By providing such through-holes 31 next to each heat sensing element 30, the area occupied by the substrate 2 around the heat sensing elements 30 can be reduced, and the transfer of heat from the heat sensing elements 30 to the substrate 2 and subsequent decrease in temperature can be suppressed. In other words, the thermal insulation is improved by the through-holes 31. It is desirable that the opening area of ​​the through-hole 31 is larger than the surface area of ​​the heat sensing element 30 (for example, the surface area viewed from above the substrate 2).

[0047] (2.4) Heat detection unit and smoke detection unit As described above, the thermal sensing unit 3 has four thermal sensing elements 30 mounted on the first surface 21 of the substrate 2 (only one is shown in Figure 4). The number of thermal sensing elements 30 is not particularly limited and may be one, but it is preferable to have at least two or more. In this embodiment, the thermal sensing elements 30 are chip thermistors that detect the heat of the gas flowing in from the opening 7 and are surface-mounted on the substrate 2. Each thermal sensing element 30 is arranged to face a different opening 7. The positional relationship of the thermal sensing elements 30 with respect to the flow path 6 and the opening 7 will be explained in detail later in the section "(2.7) Arrangement structure of the thermal sensing unit".

[0048] The thermal sensing unit 3 is electrically connected to the control unit 9 via pattern wiring formed on the substrate 2. Each thermal sensing 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 thermal sensing element 30, which may change depending on the temperature rise, through the electrical signals output from each thermal sensing element 30.

[0049] The thermal detection unit 3 may further include, in addition to the thermal detection element 30, an amplification circuit for amplifying the electrical signal from the thermal detection element 30, and a conversion circuit for analog-to-digital conversion, or the amplification and conversion may be performed on the circuit module side.

[0050] The smoke detection unit 4 is located in the center of the internal space SP1 and is configured to detect smoke. Specifically, the smoke detection unit 4 is located on the upper surface of the main body 200 of the substrate 2, and its upper part is housed in a recess 521 of the back cover 52. The smoke detection unit 4 is, for example, a photoelectric sensor that detects smoke. As shown in Figure 4, the smoke detection unit 4 includes an optical element 41 that emits light, a light-receiving element 42 that receives light emitted from the optical element 41, and a labyrinth section 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 section 43 is formed inside a case having a flattened, roughly cylindrical outer shell. The case of the smoke detection unit 4 has a plurality of openings on its outer circumferential surface for introducing gas into the labyrinth section 43, and has a structure that suppresses external light from entering the interior.

[0051] The optical element 41 and the light-receiving element 42 are arranged within the labyrinth section 43 so as not to face each other. In other words, the light-receiving surface of the light-receiving element 42 is positioned so as to be off the optical axis C1 (see Figure 3A) of the light emitted by the optical element 41.

[0052] In the event of a fire or other incident, smoke can enter the housing 5 through the opening 7 and be introduced into the labyrinth section 43. If there is no smoke in the labyrinth section 43, the light emitted from the optical element 41 hardly 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 from 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 from the optical element 41 that has been scattered by the smoke using the light-receiving element 42.

[0053] 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) to the control unit 9 that indicates a voltage level corresponding to the amount of light received by the light-receiving element 42. The control unit 9 converts the amount of light in the detection signal received from the smoke detection unit 4 into smoke concentration and makes a fire determination. The control unit 9 may use the amount of light directly for threshold determination. Alternatively, 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 to the control unit 9 that indicates a voltage level corresponding to the smoke concentration.

[0054] The smoke detection unit 4 may further include an amplification circuit for amplifying the electrical signal from the light-receiving element 42, and a conversion circuit for analog-to-digital conversion, or the amplification and conversion may be performed on the circuit module side. Also, the number of optical elements 41 for smoke detection is not limited to one, but may be multiple.

[0055] (2.5) Display section The display unit 8 has a pair of light sources 81 and a pair of guide sections 82. Each light source 81 is configured as a package-type LED, for example, with at least one LED chip mounted in the center of the mounting surface of a flat mounting substrate. Each light source 81 is mounted on the substrate 2 as described above. Each guide section 82 is a light-transmitting portion formed in a substantially L-shape. Each guide section 82 faces the corresponding light source 81 on the substrate 2 and has an incident surface into which light emitted from the light source 81 enters. Each guide section 82 has an exit surface into which light incident from the incident surface exits the guide section 82. The exit surfaces of each guide section 82 are exposed through the corresponding holes 513 of the front cover 51.

[0056] The display unit 8 is an indicator light that notifies the outside of the operating status of the detector 1. Under normal conditions (when monitoring for 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 flashing or lighting 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.

[0057] (2.6) Control Unit The control unit 9 is, for example, composed of a microcontroller primarily consisting of a CPU (Central Processing Unit) and memory. In other words, the control unit 9 is implemented in a computer having a CPU and memory, and the computer functions as the control unit 9 by the CPU executing a program stored in memory. Here, the program is pre-recorded in memory, but it may also be provided via telecommunication lines such as the Internet, or recorded on a recording medium such as a memory card.

[0058] The control unit 9 is configured to control the communication unit 11 and the circuit modules (such as the lighting circuit and power supply circuit).

[0059] 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 if it finds even one heat detection element 30 whose signal level (corresponding to the resistance value) included in the detection signal exceeds (or falls below) a threshold, it determines that a fire has occurred. The control unit 9 also monitors the detection signal from the smoke detection unit 4, and if the signal level (corresponding to the amount of light received by the light receiving element 42 or the smoke density) included in the detection signal exceeds a threshold, it determines that a fire has occurred.

[0060] When the control unit 9 determines that a fire has occurred based on heat detection or smoke detection, it transmits a signal to the receiver and fire alarm of the automatic fire alarm system via the communication unit 11 to indicate the occurrence of the fire. 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 connected to the receiver and fire alarm, for communication purposes via the connecting piece 101 of the mounting unit 10, the connector part of the mounting base, and signal lines wired on the back of the structure X1. When the control unit 9 determines that a fire has occurred, it also outputs a control signal to the lighting circuit of the circuit module to cause the light source 81 of the display unit 8 (operating light) to blink or light up.

[0061] (2.7) Arrangement structure of the heat sensing unit The arrangement structure of the heat detection unit 3 in this embodiment will now be described.

[0062] 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. Therefore, the sensor 1 as a whole can be made smaller (especially thinner). In addition, compared to a lead-type thermistor, the cost of the thermistor itself and its mounting cost can be kept low.

[0063] Furthermore, in this embodiment, at least a portion of the first surface 21 (front surface) of the substrate 2 is exposed to the flow channel 6. Here, the smoke detection unit 4 is located in the center of the first surface 21, and the central part of the internal space SP1 of the housing 5 is generally occupied by the smoke detection unit 4. The flow channel 6 substantially corresponds to the space surrounding the central part (smoke detection unit 4) of the internal space SP1. In other words, the flow channel 6 is roughly donut-shaped. Therefore, in this embodiment, the peripheral area of ​​the first surface 21 of the substrate 2, excluding the mounting area of ​​the smoke detection unit 4, is exposed to the flow channel 6. The peripheral area also includes the upper surfaces of the eight extensions (201-204) described above.

[0064] In this way, because the peripheral region of the first surface 21 of the substrate 2 is exposed to the flow channel 6, the four heat sensing elements 30 located in the first extension 201 and the third extension 203 can be more likely to be exposed to the gas flowing through the flow channel 6, even though they are chip thermistors.

[0065] In other words, for example, when a heated gas rises from below due to a fire, it is introduced into the housing 5 through 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 that of a fire, and the detector 1 can quickly determine that a fire has occurred. As a result, the heat detection performance of the detector 1 can be improved while the detector 1 can be made smaller.

[0066] In this embodiment, the detector 1 is further equipped with 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 above a specified level, smoke can also be detected. Thus, it is possible to improve the fire detection performance while miniaturizing the detector 1 as a whole.

[0067] In this embodiment, each heat sensing element 30, which is a chip thermistor, is positioned to face a different opening 7. In Figure 1, the heat sensing element 30 on the left is positioned to face one opening 7 on the left, and the heat sensing element 30 on the right is positioned to face another opening 7 on the right. Each heat sensing element 30 is positioned so that, when viewed from the external space SP2 side, the opening region 70 of the corresponding opening 7 (see Figures 1 and 5) is contained within a roughly rectangular opening region 70. In short, the area of ​​the heat sensing element 30 projected onto the opening region 70 is contained within the opening region 70. Therefore, compared to the case where at least a portion of the heat sensing element 30 is positioned outside the opening region 70, i.e., hidden behind the cylindrical body 510 or the crossbar 512 of the housing 5, the possibility of exposure to gas entering through the opening 7 can be increased.

[0068] In particular, in this embodiment, each heat sensing element 30, which is a chip thermistor, is located in the center of the opening region 70 in the direction perpendicular to the first surface 21 (vertical direction) when the opening region 70 is viewed from the side of the external space SP2, as shown in Figure 5. In other words, the positional relationship between the opening 7 and the substrate 2 is defined so that each heat sensing element 30 is located in the center of the opening region 70. This positional relationship is adjusted, for example, by the amount of protrusion of the rib 514 (see Figure 1) that protrudes from the back side of the base 511 of the front cover 51 and contacts the substrate 2, and the amount of insertion of the connecting piece 101 of the mounting part 10. With such a positional relationship, for example, compared to the case where the heat sensing element 30 is located closer to one end of the opening region 70 (closer to the upper end or lower end), the possibility of the heat sensing element 30 being exposed to gas entering through the opening 7 can be further increased.

[0069] Furthermore, in this embodiment, each heat sensing element 30 is not simply positioned to the side of the smoke detection unit 4, but is positioned near the opening 7. In other words, if the flow path 6 is divided into a first path 61 located on the side of the opening 7 and a second path 62 connected to the first path 61 and located on the side of the central part of the internal space SP1, each heat sensing element 30, which is a chip thermistor, is located in the first path 61 (see Figure 1). Therefore, the responsiveness of the sensor 1 to heat detection can be improved compared to, for example, the case where the chip thermistor is located in the second path 62. As previously mentioned, Figure 1 schematically illustrates the flow path 6 with arrow lines, but in reality, the first path 61 corresponds to the outer half of the air gap around the smoke detection unit 4 in the internal space SP1, and the second path 62 corresponds to the inner half of the air gap.

[0070] By the way, in the thickness direction (vertical direction) of the substrate 2, it is preferable that the center P1 of the internal space of the labyrinth section 43 is located between the heat sensing element 30, which is a chip thermistor, and the mounting surface 55 in the vertical direction (see Figure 1). In other words, the heat sensing element 30 is located below the center P1 in the vertical direction. In Figure 3A, the optical element 41 and the light receiving element 42 arranged in the labyrinth section 43 are schematically shown as dots. In this embodiment, the heights of the optical element 41 and the light receiving element 42 are the same, and the intersection point 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.

[0071] The height positions of the optical element 41 and the light-receiving element 42, and the orientations 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. Also, 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.

[0072] Because the central point P1 is located between the heat sensing element 30 and the mounting surface 55, the smoke (gas) that has passed through the heat sensing element 30 can be effectively guided to the smoke detection unit 4, despite the characteristic of an upward airflow generated when a heated gas flows through the flow path 6 inside the housing 5. Therefore, in a detector 1 that detects not only heat but also smoke, the fire detection performance can be further enhanced while the overall size of the detector 1 can be reduced.

[0073] (3) Variant The above embodiments are merely one of many embodiments of this disclosure. The above embodiments can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved. Furthermore, functions similar to those of the sensor 1 according to the above embodiments may be embodied in a control method for the sensor 1, a computer program, or a non-temporary recording medium on which the computer program is stored.

[0074] The following lists modifications of the above embodiment. The modifications described below can be combined and applied as appropriate. In the following, the above embodiment may also be referred to as the "basic example."

[0075] The control unit 9 of the sensor 1 in this disclosure includes a computer system. The computer system mainly consists of a processor and memory as hardware. The function of the control unit 9 of the sensor 1 in this 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 via a telecommunications line, or provided on a non-temporary recording medium such as a memory card, optical disk, or hard disk drive that can be read by the computer system. The processor of the computer system consists of one or more electronic circuits including semiconductor integrated circuits (ICs) or large-scale integrated circuits (LSIs). The integrated circuits such as ICs and LSIs referred to here are named differently depending on the degree of integration, and include integrated circuits called system LSIs, VLSIs (Very Large Scale Integration), or ULSIs (Ultra Large Scale Integration). Furthermore, FPGAs (Field-Programmable Gate Arrays) that are programmed after the manufacture of LSIs, or logic devices that allow for the reconfiguration of junction relationships or circuit compartments within LSIs, can also be used as processors. Multiple electronic circuits may be integrated onto a single chip or distributed across multiple chips. Multiple chips may be integrated onto a single device or 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 also consists of one or more electronic circuits, including semiconductor integrated circuits or large-scale integrated circuits.

[0076] Furthermore, it is not essential for the sensor 1 to have multiple functions in the control unit 9 of the sensor 1 integrated into a single housing; the components of the sensor 1 may be distributed across multiple housings. Moreover, at least some of the functions of the sensor 1, for example, some of the functions of the sensor 1, may be implemented by the cloud (cloud computing), etc. Conversely, as in the basic example, multiple functions of the sensor 1 may be integrated into a single housing.

[0077] (3.1) Variation 1 The following description of the sensor 1A of this modified example (Modification 1) will be made with reference to Figure 6. Components that are generally common to the sensor 1 of the basic example will be given the same reference numerals, and their explanations may be omitted as appropriate. Figure 6 shows a schematic cross-sectional view of sensor 1A.

[0078] Detector 1A differs from the basic example in that it includes an airflow adjustment unit Z1 within the internal space SP1. The airflow adjustment unit Z1 extends from the lower edge of the cylindrical body 510 on the front cover 51 of the housing 5 toward the smoke detection unit 4. When viewed from above, the airflow adjustment unit Z1 is a roughly donut-shaped plate member. The airflow adjustment unit Z1 may be formed integrally with the front cover 51, or it may be a separate member fixed to the front cover 51 by screws or the like.

[0079] The airflow adjustment unit 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 unit Z1 is inclined toward the mounting surface 55 as it moves toward the center of the internal space SP1.

[0080] In other words, in sensor 1A, because the airflow adjustment unit Z1 is provided, the opening cross-sectional area of ​​the first passage 61 is set to be smaller than the opening cross-sectional area of ​​the second passage 62. Therefore, the gas that enters the flow path 6 through the opening 7 can be promoted to flow from the narrow space of the first passage 61 towards the wider space of the second passage 62.

[0081] In particular, because the airflow adjustment section Z1 is inclined towards the installation surface 55 from a certain point, the second path 62 widens towards the installation surface 55 as it moves from the first path 61 towards the central part. Therefore, in response to the characteristic that an upward airflow is generated when a heated gas flows through the flow path 6 inside the housing 5, the smoke (gas) that has passed through the heat sensing element 30 can be effectively guided to the smoke detection section 4.

[0082] (3.2) Variation 2 The following description of the modified example (modified example 2) of detector 1B will be made with reference to Figure 7. Components that are generally common to detector 1 of the basic example will be given the same reference numerals, and their explanations may be omitted as appropriate. Figure 7 shows a schematic cross-sectional view of detector 1B.

[0083] Detector 1B differs from the basic example in that the smoke detection unit 4 is mounted on the second surface 22 of the circuit board 2, rather than the first surface 21. The heat detection element 30 is mounted on the first surface 21, as in the basic example.

[0084] In the housing 5 of this detector 1B, the smoke detection unit 4 is mounted on the second surface 22 (bottom surface), so the front cover 51 has a recessed area 515 for housing the smoke detection unit 4. Specifically, the base 511 of the front cover 51 is formed so that its central part is convex downwards. In the basic example, the back cover 52 has a recessed area 521 for housing the upper part of the smoke detection unit 4 (see Figure 1).

[0085] The base portion 511 has a hole 5111 in the peripheral wall of its convex portion 5110 that allows gas (smoke) to be introduced into the housing 5.

[0086] Furthermore, the flow path 6 is configured to split into two branches, an upper flow path 6X and a lower flow path 6Y, with the substrate 2 as the dividing line. The heated gas passing through the upper flow path 6X will pass through the heat sensing element 30. A portion of the gas passing through the lower flow path 6Y will rise to the upper flow path 6X through the through-hole 31 in the substrate 2 (see Figure 3B) and pass through the heat sensing element 30. The remaining gas passing through the lower flow path 6Y will continue towards the smoke detection unit 4 in the central part.

[0087] (3.3) Modification example 3 The following description of the sensor 1C of this modified example (modification 3) will be made 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 descriptions may be omitted as appropriate. Figure 8A is a perspective view of the sensor 1C seen from below, and Figure 8B is a plan view of the sensor 1C seen from below, with a portion (only the substrate 2) transparent.

[0088] Detector 1C is, as an example, a type P (Proprietary-type) heat detector that transmits a fire signal to the outside using a so-called type P communication method. Detector 1C has a heat detection unit 3, similar to the basic example, but unlike the basic example, it does not have a smoke detection unit 4. In other words, detector 1C determines the occurrence of a fire or other incident solely by detecting heat.

[0089] Another difference between detector 1C and the basic example is that detector 1C has three heat detection elements 30 (the basic example has four).

[0090] As shown in Figure 8B, the substrate 2 of the sensor 1C has a roughly diamond shape when viewed from below. Two of the three heat sensing elements 30 are surface-mounted on the first surface 21 (top surface) of the diamond-shaped substrate 2. These two heat sensing elements 30 are positioned diagonally opposite each other in the left-right direction on the first surface 21 (top surface). Specifically, the substrate 2 has a pair of protrusions 23 that project outward (with a slight inclination relative to the left-right direction) on both edges at the diagonal positions. A corresponding heat sensing element 30 is positioned on the top surface of each protrusion 23. The other heat sensing element 30 is positioned on the top surface of the central part of the substrate 2.

[0091] Similar to the basic example, through-holes 31 are provided near each heat sensing element 30 to improve thermal insulation. However, for the heat sensing element 30 located in the center of the substrate 2, two semicircular through-holes 31 are arranged so as to sandwich the heat sensing element 30 between them.

[0092] The front cover 51 of the sensor 1C has one inlet (vertical hole) 7B and two auxiliary openings (vertical holes) 56 at its base 511. The two auxiliary openings 56 are located near the left and right edges of the base 511, and the inlet 7B is located in the center of the base 511. Each of the inlet 7B and the two auxiliary openings 56 penetrates the base 511 of the front cover 51 in the thickness direction. The two auxiliary openings 56 near the left and right edges of the base 511 have roughly crescent-shaped openings, and the inlet 7B in the center of the base 511 has a roughly circular opening. The pair of protrusions 23 of the substrate 2 are opposite each other so as to correspond one-to-one with the two auxiliary openings 56, and the central part of the substrate 2 faces the central inlet 7B. As a result, the protrusion 23 and the central part of the substrate 2 are exposed through the two auxiliary openings 56 and the inlet 7B, respectively, as shown in Figure 8B. Therefore, the rising hot gas enters the housing 5 through the two auxiliary openings 56 and the inlet 7B, and then flows into the first surface 21 (top surface) through the through hole 31. Thus, the heat sensing element 30 is easily exposed not only to the gas flowing in from the opening 7 (side opening 7A: lateral hole), but also to the gas flowing in from the two auxiliary openings 56 and the inlet 7B.

[0093] Even with this configuration, it is possible to further improve fire detection performance while also miniaturizing (especially thinning) the detector 1C as a whole.

[0094] (3.4) Modification 4 The following description of the sensor 1D of this modified example (Modification 4) will be made 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 descriptions may be omitted as appropriate. Figure 9A is a perspective view of the sensor 1D seen from below, and Figure 9B is a plan view of the sensor 1D seen from below, with a portion (only the substrate 2) transparent.

[0095] Detector 1D is, for example, 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, similar to the basic example, but unlike the basic example, it does not have a smoke detection unit 4. In other words, like detector 1C in Modification 3, detector 1D determines the occurrence of a fire or other incident solely by detecting heat.

[0096] Another difference between detector 1D and the basic example is that detector 1D has five heat detection elements 30 (the basic example has four).

[0097] The substrate 2 of the sensor 1D has a shape somewhat similar to the substrate 2 of the basic example, as shown in Figure 9B. Specifically, the substrate 2 of the sensor 1D has a circular main body 200 and a plurality of extensions (six in the illustrated example) that extend away from the center of the main body 200 at its edge. Hereinafter, the six extensions will be referred to as a pair of first extensions 201, a pair of second extensions 202, and a pair of third extensions 203. One of the five heat sensing elements 30 is located in the center of the main body 200, and the remaining four heat sensing elements 30 and the two light sources 81 are located in the six extensions (201, 202, and 203), respectively.

[0098] A pair of first extensions 201 extend from the left and right edges of the main body 200, respectively, in directions away from each other. Each first extension 201 has a narrower small piece Y1 at its tip. A corresponding heat sensing element 30 is positioned on the upper surface of each small piece Y1.

[0099] A pair of second extensions 202 extend from the front and rear edges of the main body 200, each in a direction away from the others. The extension amount of the second extensions 202 is less than that of the other extensions. A corresponding light source 81 is positioned on the upper surface of each second extension 202.

[0100] The pair of third extensions 203 extend away from each other from positions slightly offset counterclockwise from the front and rear edges of the main body 200 when viewed from below the substrate 2. Specifically, the front third extension 203 is positioned to the left of the front second extension 202, and the rear third extension 203 is positioned to the right of the rear second extension 202. Each third extension 203, like the first extension 201, has a narrower small piece Y1 at its tip. A corresponding heat sensing element 30 is positioned on the upper surface of each small piece Y1.

[0101] In short, the circuit board 2 of sensor 1D has a shape that is symmetrical twice, for example, by rotating it 180 degrees around its center.

[0102] Also, as in the basic example, through holes 31 are provided near each heat sensing element 30 to improve thermal insulation. However, for the heat sensing element 30 located in the center of the substrate 2, two semicircular through holes 31 are arranged so as to sandwich the heat sensing element 30 between them. Also, as in the basic example, a pair of guide parts 82 of the display unit 8 are exposed on the front cover 51 of the sensor 1D.

[0103] The front cover 51 of the sensor 1D has one inlet (vertical hole) 7B and two auxiliary openings (vertical holes) 57 in its base 511. The two auxiliary openings 57 are located near the left and right edges of the base 511, and the inlet 7B is located in the center of the base 511. Each of the two auxiliary openings 57 and the inlet 7B penetrates the base 511 of the front cover 51 in the thickness direction. The two auxiliary openings 57 located near the left and right edges of the base 511 have a substantially rectangular opening, and the inlet 7B in the center of the base 511 has a substantially circular opening. The tips of the small pieces Y1 in the pair of first extensions 201 of the substrate 2 face the two auxiliary openings 57 on the left and right in a one-to-one correspondence, and the central part of the substrate 2 faces the central inlet 7B. As a result, the tip of the small piece Y1 and the central part of the substrate 2 are exposed through the two auxiliary openings 57 and the inlet 7B, respectively, as shown in Figure 9B. Therefore, the rising hot gas enters the housing 5 through the two auxiliary openings 57 and the inlet 7B, and then flows into the first surface 21 (top surface) through the through hole 31. Thus, the heat sensing element 30 is easily exposed not only to the gas flowing in from the opening 7 (side opening 7A: lateral hole), but also to the gas flowing in from the two auxiliary openings 57 and the inlet 7B.

[0104] In this configuration, it is possible to further improve fire detection performance while also miniaturizing (especially thinning) the detector 1D as a whole.

[0105] (3.5) Modification 5 The following description of the sensor 1E of this modified example (Modification 5) will be made 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 descriptions may be omitted as appropriate. 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) transparent.

[0106] Detector 1E is a fire alarm that, for example, outputs an alarm sound when a fire occurs. Like the basic example, detector 1E is equipped with a heat detection unit 3, but unlike the basic example, it is not equipped with a smoke detection unit 4. In other words, detector 1E, like detector 1C in Modification 3 and detector 1D in Modification 4, determines the occurrence of a fire or the like solely by detecting heat.

[0107] Furthermore, detector 1E differs from the basic example in that it is equipped with a speaker and an acoustic circuit that outputs sounds such as alarm tones. Also, detector 1E is, for example, a battery-operated fire alarm. Therefore, detector 1E has a battery and a space for housing the battery. In detector 1E, the operating unit U1 is exposed on the front of the front cover 51.

[0108] The control unit U1 accepts external operation. The control unit U1 can be pushed upward by a user's finger or the like. The control unit U1 is a translucent, disc-shaped component. The control unit U1 is positioned opposite the indicator light inside the housing 5. Furthermore, the control unit U1 is configured to press a push-button switch inside the housing 5 when pressed. For example, if the control unit U1 is pressed while an alarm is sounding, the alarm sound output will stop. The control unit U1 also lights up when the sensor 1E is operating or when the battery runs out. Operational tests can also be performed by operating the control unit U1.

[0109] Another difference between detector 1E and the basic example is that it has three heat detection elements 30 (the basic example has four).

[0110] As shown in Figure 10B, the circuit board 2 of the sensor 1E has an inverted Y shape when viewed from below. Since the sensor 1E houses or supports relatively large components such as a speaker, battery, and operating unit U1 within the housing 5, the circuit board 2 has an inverted Y shape to save space and avoid these components.

[0111] Specifically, the substrate 2 of the sensor 1E has a circular main body 200 with a cut-off on the left side, and multiple (three in the illustrated example) extensions extending away from the center of the main body 200 at its edge. Hereinafter, the three extensions will be referred to as extension pieces 205. The three heat sensing elements 30 are each arranged on the three extension pieces 205.

[0112] Of the three extension pieces 205, the front extension piece 205 extends from the front edge of the main body 200, and a corresponding heat sensing element 30 is positioned on the upper surface of its tip. Of the three extension pieces 205, the two rear extension pieces 205 extend from positions slightly offset to the left and right from the rear edge of the main body 200, and two corresponding heat sensing elements 30 are positioned on the upper surfaces of their respective tips.

[0113] Also, similar to the basic example, through holes 31 (a total of 3) are provided near the inside of each heat sensing element 30 to improve thermal insulation.

[0114] The front cover 51 of the sensor 1E has an auxiliary opening (vertical hole) 58 in its base 511. The auxiliary opening 58 is located near the front edge of the base 511. The auxiliary opening 58 penetrates the base 511 of the front cover 51 in the thickness direction. The auxiliary opening 58 has a roughly rectangular opening. The tip of the front extension piece 205 of the three extension pieces 205 faces the auxiliary opening 58. As a result, the tip of the front extension piece 205 is exposed from the auxiliary opening 58, as shown in Figure 10B. Therefore, rising hot gas enters the housing 5 through the auxiliary opening 58 and then flows into the first surface 21 (top surface) through the through hole 31. Thus, the heat sensing element 30 is easily exposed not only to gas flowing in from the opening 7 (side opening 7A: horizontal hole) but also to gas flowing in from the auxiliary opening 58.

[0115] Even with this configuration, it is possible to further improve fire detection performance while also making the detector 1E as a whole smaller (especially thinner).

[0116] (3.6) Other variations Unlike the basic example of detector 1 (combined fire detector) in modifications 3 to 5, the front cover 51 does not have vertical holes. However, similar to modifications 3 to 5, detector 1 (combined fire detector) may have one or more auxiliary openings (vertical holes) 59 (two in the illustrated example) in the front cover 51, as shown in Figure 11.

[0117] In the basic example, the thermal sensing element 30 is mounted on the first surface 21 (top surface) of the substrate 2. However, the thermal sensing element 30 may also be mounted on the second surface 22 (bottom surface) of the substrate 2. Alternatively, some of the multiple thermal sensing elements 30 may be mounted on the first surface 21 and the rest on the second surface 22. Furthermore, for example, both the thermal sensing element 30 and the smoke detection unit 4 may be mounted on the second surface 22 (bottom surface) of the substrate 2.

[0118] In the basic example, there is one through-hole 31 adjacent to a single heat sensing element 30, but as shown in modified examples 3 and 4, there may be two or more. For example, multiple through-holes 31 may be provided so as to surround a single heat sensing element 30.

[0119] In the basic example, the thermal sensing element 30 is mounted on the first surface 21 of the substrate 2, and the through-holes 31 are located adjacent to it. However, even if the thermal sensing element 30 is mounted on the second surface 22 of the substrate 2, it is desirable that the through-holes 31 be located adjacent to it.

[0120] In the basic example, board 2 is composed of a single printed circuit board. However, board 2 may be composed of two or more printed circuit boards. However, it is desirable that the multiple divided printed circuit boards be arranged on the same plane.

[0121] In the basic example, the opening 7 is a lateral hole formed in the peripheral wall of the housing 5. However, the opening 7 referred to in this disclosure may not be a lateral hole, but may correspond to the inlet (vertical hole) 7B, auxiliary openings (vertical holes) 56-58, and the aforementioned auxiliary opening (vertical hole) 59 in modified examples 3-5.

[0122] (Embodiment 2) Hereinafter, the detector 1F according to this embodiment will be described with reference to Figures 12A and 12B. The detector 1F according to this embodiment differs from the detectors (1, 1A to 1E) of Embodiment 1 (including modified versions) in that it further comprises a shielding portion V1. Hereinafter, components substantially the same as those in Embodiment 1 will be denoted by the same reference numerals and their descriptions will be omitted as appropriate. The shielding portion V1 of this embodiment may also be appropriately applied to the detectors (1, 1A to 1E) of Embodiment 1.

[0123] Furthermore, the detector 1F shown in Figures 12A and 12B is, as an example, a type P heat detector, similar to the detector 1C (Figures 8A and 8B) in Modification 3 of Embodiment 1. Also, like the detector 1C in Modification 3 of Embodiment 1, the detector 1F does not have a smoke detection unit 4 and is a heat detector that determines the occurrence of a fire or the like solely by detecting heat.

[0124] In this embodiment as well, the thermal sensing element 30 (chip thermistor) is positioned so as to fit within the opening region 70 of the opening 7 (side opening 7A: lateral hole) when viewed from the external space SP2 side. The shielding portion V1 is configured to block a portion of the opening region 70 on the external space SP2 side of the thermal sensing element 30 (chip thermistor).

[0125] The shielding section V1 has a pair of columns V11. Here, the shielding section V1 is composed of a pair of columns V11. Each column V11 is elongated in the vertical direction (for example, in the thickness direction of the substrate 2). Each column V11 is formed integrally with the front cover 51 of the housing 5. Specifically, the first end (upper end) of each column V11 is connected to the cylindrical body 510 of the housing 5, and the second end (lower end) of each column V11 is connected to the base 511. As a result, each column V11 extends from the upper edge to the lower edge of the opening 7 (side opening 7A).

[0126] The pair of columns V11 are positioned at a predetermined distance L1 apart in a direction D1 (here, the left-right direction) perpendicular to the direction in which the back cover 52 and the front cover 51 are aligned, when the opening area 70 is viewed from the side of the external space SP2. Hereinafter, as an example, the back 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 back cover 52 corresponding to the second cover and the front cover 51 corresponding to the first cover.

[0127] Here, as an example, the specified distance L1 is the distance specified so that the test finger cannot enter. The test finger is, for example, a simulated finger as specified in Appendix 4, 1(2)c of the Japanese Electrical Appliances and Materials Safety Act.

[0128] The thermal sensing element 30 is positioned between a pair of pillars V11 in direction D1 when the opening region 70 is viewed from the side of the external space SP2 (see Figure 12A). In other words, the thermal sensing element 30 is exposed from between the pair of pillars V11.

[0129] In this way, by further providing the shielding section V1, the sensor 1F makes it less likely for heat to flow in from the opening 7 to be obstructed, while also reducing the possibility of, for example, a person's finger or a tool coming into contact with the chip thermistor unintentionally.

[0130] Incidentally, as shown in Figure 12B, each column V11 has a guide surface V2 that guides the airflow from the external space SP2 toward the heat sensing element 30 (chip thermistor). Here, the cross-sectional shape of each column V11 when cut along the horizontal direction is approximately semi-elliptical, and its curved surface corresponds to the guide surface V2. The tip of this semi-elliptical shape is pointed toward the heat sensing element 30. Therefore, the possibility of heat inflow from the opening 7 being obstructed by the shielding portion V1 can be further reduced.

[0131] Next, a modification 1 of this embodiment will be described. In the example shown in Figures 12A and 12B above, the number of columns V11 in the shielding section V1 is two, but the number of columns in the shielding section V1 is not particularly limited. Figures 13A and 13B show the detector 1G of modification 1. The detector 1G of modification 1 differs from the detector 1F in that the number of columns in the shielding section V1 is three.

[0132] The sensor 1G in Modification Example 1 is a type P heat detector as an example. Note that the protrusion 23 on the circuit board 2 of sensor 1F protrudes slightly diagonally with respect to the radial direction of the housing 5 when viewed along the vertical direction (see Figure 12B), whereas the protrusion 23 on the circuit board 2 of sensor 1G protrudes outward along the radial direction of the housing 5 (see Figure 13B).

[0133] The shielding section V1 of the sensor 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 elongated in the vertical direction (for example, in 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 cylindrical body 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.

[0134] Each of the pair of first columns V12 and the second column V13 are positioned with a predetermined distance L2 between them in direction D1 (in this case, left-right direction) when viewing the opening area 70 from the side of the external space SP2. Here, as an example, the predetermined distance L2 is a distance specified so that a test finger cannot enter.

[0135] The thermal sensing element 30 is positioned between a pair of first pillars V12 in direction D1 when viewing the opening region 70 from the external space SP2 (see Figure 13A). However, the thermal sensing element 30 is located in a position that overlaps with the second pillar V13 when viewing the opening region 70 from the external space SP2. In other words, the thermal sensing element 30 is hidden behind the second pillar V13 and cannot be seen.

[0136] In this way, the sensor 1G is equipped with a shielding section V1 having three pillars, which makes it less likely for heat to flow in from the opening 7 to be obstructed, while further reducing the possibility of a person's finger or tool coming into contact with the chip thermistor.

[0137] Incidentally, each of the pair of first columns V12 has an induction surface V2 that guides the airflow from the external space SP2 toward the heat sensing element 30 (chip thermistor), as shown in Figure 13B. Here, each of the pair of first columns V12 has a cross-sectional shape that is roughly a racetrack shape, elongated along the outer edge of the housing 5 when cut horizontally, and has semi-circular curved surfaces as induction surfaces V2 on both its left and right sides. Therefore, the possibility of heat inflow from the opening 7 being obstructed by the shielding portion V1 can be further reduced. The second column V13 has a cross-sectional shape that is roughly rectangular when cut horizontally, but may also have a roughly racetrack shape and an induction surface V2, similar to the first column V12.

[0138] Figure 13C shows another example of the sensor 1G of Modification 1. In this other example, each of the pair of first columns V12 has a roughly trapezoidal cross-sectional shape when cut along the horizontal direction. Each first column V12 is configured such that of the two parallel sides in the trapezoid, the shorter side faces the heat sensing element 30 and the longer side faces the external space SP2. In particular, each first column V12 has an inclined surface on the first surface V121 facing the middle second column V13, and on the second surface V122 opposite to the first surface V121, both of which are inclined toward the heat sensing element 30. The inclination angle of the second surface V122 with respect to the radial direction of the housing 5 is greater than the inclination angle of the first surface V121. The middle second column V13 has a bullet-shaped cross-sectional shape when cut along the horizontal direction, which is longer in the radial direction of the housing 5, and the side facing the heat sensing element 30 is semi-circular. In this alternative example, the first surface V121, the second surface V122, and the end face with a semicircular cross-section correspond to the guide surface V2. In short, in this alternative example, each of the pair of first columns V12 has a guide surface V2. In this alternative example as well, the presence of the guide surface V2 further reduces the possibility that the shielding portion V1 will obstruct the heat inflow from the opening 7.

[0139] Next, a modified example 2 of this embodiment will be described. Figures 14A to 14C and Figure 15 show the sensor 1H of modified example 2. The sensor 1H of modified example 2 is, for example, an R-type heat sensor. The protrusion 23 of the substrate 2 of the sensor 1H protrudes outward along the radial direction of the housing 5.

[0140] In the sensor 1H of the modified example 2, the shielding portion V1 has a pair of first protrusions V14 and a 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 back cover 52 (first cover), which covers the substrate 2 from one direction in the thickness direction of the substrate 2 (here, from above), toward the front cover 51 (second cover). The front cover 51 covers the substrate 2 from the opposite direction in the thickness direction of the substrate 2 (here, from below). The second protrusion V15 protrudes from the front cover 51 toward the back cover 52. Each of the pair of first protrusions V14 and second protrusions V15 is elongated along the vertical direction (here, for example, the thickness direction of the substrate 2).

[0141] As shown in Figure 15, the pair of first protrusions V14 are formed integrally with the back cover 52. Specifically, the pair of first protrusions V14 project downward continuously from the peripheral edge of the lower surface of the back cover 52. Note that the tips of each of the pair of first protrusions V14 do not come into contact with the front cover 51, leaving a gap between them.

[0142] The pair of first protrusions V14 are positioned in direction D1 with a predetermined distance L3 between them when viewing the opening region 70 from the side of the external space SP2. Here, as an example, the predetermined distance L3 is defined as a distance that prevents a test finger from entering. The heat sensing element 30 is positioned between the pair of first protrusions V14 in direction D1 when viewing the opening region 70 from the side of the external space SP2 (see Figure 14A).

[0143] The second projection V15 is positioned in the center between the pair of first projections V14 in direction D1. In other words, each of the pair of first projections V14 is positioned offset from the second projection V15 in direction D1 when viewing the opening region 70 from the side of the external space SP2. This further reduces the possibility that the shielding portion V1 will obstruct the heat inflow from the opening 7.

[0144] The second projection V15 is formed integrally with the front cover 51. Specifically, the second projection V15 protrudes upward continuously from the peripheral edge of the upper surface of the front cover 51. The tip of the second projection V15 does not contact the upper edge of the opening 7, leaving a gap between it and the upper edge.

[0145] As shown in Figure 14A, the second projection V15 is located in the same position as the chip thermistor in direction D1 when the opening region 70 is viewed from the side of the external space SP2. However, the amount of protrusion of the second projection V15 is defined so that at least a portion of the chip thermistor is exposed. Specifically, the amount of protrusion is defined so that the tip of the second projection V15 does not exceed the upper surface of the chip thermistor. For example, the tip of the second projection V15 is located below the lower surface of the substrate 2, and the heat sensing element 30 is exposed between the pair of first projections V14 without being hidden behind the second projection V15.

[0146] By specifying the amount of protrusion of the second projection V15 so that at least a portion of the chip thermistor is exposed, it is possible to further reduce the likelihood of heat inflow from the opening 7 being obstructed while also reducing the possibility of a person's finger or tool coming into contact with the chip thermistor.

[0147] Incidentally, each of the pair of first protrusions V14 also has a guide surface V2, as shown in Figure 14B. Here, each of the pair of first protrusions V14 has a cross-sectional shape that is elongated elliptical along the radial direction of the housing 5 when cut horizontally, and has curved surfaces as guide surfaces V2 on both its left and right sides. Therefore, the possibility of heat inflow from the opening 7 being obstructed by the shielding portion V1 can be further reduced. In particular, the relatively small width dimension of each first protrusion V14 further reduces the possibility of heat inflow being obstructed.

[0148] On the other hand, the second projection V15 also has a guide surface V2, as shown in Figure 14C. The second projection V15 is formed in a substantially triangular shape when viewed along the direction in which the pair of first projections V14 are aligned. In particular, the second projection V15 has a curved surface V150 that is substantially arc-shaped and inclined on the side of the internal space SP1 when viewed along the direction in which the pair of first projections V14 are aligned. This curved surface V150 also corresponds to the guide surface V2. The hot airflow can be guided toward the chip thermistor above the second projection V15 by colliding with the guide surface V2.

[0149] In this way, the sensor 1H is equipped with a shielding section V1 having three protrusions, which makes it less likely for heat to flow in from the opening 7 to be obstructed, while further reducing the possibility of a person's finger or tool coming into contact with the chip thermistor.

[0150] Furthermore, the shielding portion V1 may have, for example, another first projection V14 between the pair of first projections V14. The other first projection V14 and the second projection V15 may protrude so that their tips face each other. In this case as well, it is desirable that the amount of protrusion of the other first projection V14 is defined so that at least a part of the chip thermistor is exposed, similar to the second projection V15.

[0151] Next, a third modification of this embodiment will be described. Figure 16 shows the sensor 1I of the third modification. The sensor 1I of the third modification is, for example, an R-type heat detector.

[0152] The shielding portion V1 of the sensor 1I has a pair of first protrusions V16 that are formed integrally with the back cover 52, similar to the pair of first protrusions V14 of the sensor 1H in Modification 2. The pair of first protrusions V16 project from the back cover 52 toward the front cover 51. The heat sensing element 30 is positioned between the pair of first protrusions V16 in direction D1 when the opening region 70 is viewed from the side of the external space SP2.

[0153] The shielding portion V1 of the sensor 1I further has a pair of second projections V17. Each of the pair of second projections V17 is formed integrally with the front cover 51, similar to the second projection V15 of the sensor 1H in Modification 2. The pair of second projections V17 protrude from the front cover 51 toward the back cover 52. However, the tips of the pair of second projections V17 protrude such that they face each other one-to-one with the tips of the pair of first projections V16. In other words, there is a gap between each first projection V16 and the second projection V17 that faces it.

[0154] Furthermore, the shielding portion V1 of the sensor 1I has a column V18. The column V18 is formed integrally with the front cover 51 of the housing 5, similar to the second column V13 of the sensor 1G in the modified example 1. The heat detection element 30 is located in a position that overlaps with the column V18 when the opening area 70 is viewed from the side of the external space SP2. In other words, the heat detection element 30 is hidden behind the column V18 and is not visible.

[0155] Each of the pair of first projections V16 and the column V18 are positioned with a predetermined distance L4 between them in direction D1 when viewing the opening area 70 from the side of the external space SP2. Here, as an example, the predetermined distance L4 is also a distance specified so that a test finger cannot enter.

[0156] In this way, the sensor 1I is equipped with a shielding section V1 having four protrusions and one column, which makes it less likely for heat to flow in from the opening 7 to be obstructed, while further reducing the possibility of a person's finger or tool coming into contact with the chip thermistor.

[0157] Although not shown in the diagram, it is desirable that the shielding portion V1 of the sensor 1I also has an induction surface V2.

[0158] Next, a modified example 4 of this embodiment will be described. Figures 17A and 17B show the sensor 1J of modified example 4. The sensor 1J of modified example 4 is, for example, an R-type heat detector.

[0159] The shielding portion V1 of the sensor 1J has only one column V19. Similar to the second column V13 of the sensor 1G in the modified example 1, the column V19 is integrally formed with the front cover 51 of the housing 5. The heat detection element 30 is positioned so that it overlaps with the column V19 when the opening region 70 is viewed from the external space SP2 side. In other words, the heat detection element 30 is hidden behind the column V19 and cannot be seen.

[0160] As shown in Figure 17B, column V19 has a guide surface V2. Here, the cross-sectional shape of column V19, when cut along the horizontal direction, is a tapered shape that becomes pointed towards the internal space SP1, and this tapered surface corresponds to the guide surface V2. In addition, the cross-sectional shape of column V19 is semi-circular on both the left and right sides, and these left and right surfaces also correspond to the guide surface V2.

[0161] Thus, even though sensor 1J has only one column V19, it is possible to reduce the possibility of human fingers or tools coming into contact with the chip thermistor while minimizing obstruction of heat inflow from the opening 7. Furthermore, if reducing the possibility of human fingers or tools coming into contact with the chip thermistor is a priority, it is desirable that the number of protrusions or columns in the shielding section V1 be two or more, as in sensors 1F to 1I.

[0162] (Embodiment 3) The detector 1K according to this embodiment will be described below with reference to Figures 18A to 18C. Hereinafter, components substantially similar to those in Embodiment 1 will be denoted by common reference numerals, and their descriptions will be omitted as appropriate. The detector 1K of this embodiment differs from the detectors (1, 1A to 1E) of Embodiment 1 (including modified examples) in that its outer surface 53 has a tapered first surface 531, as described later. The tapered first surface 531 in this embodiment may also be applied to the detectors (1, 1A to 1E) of Embodiment 1 or the detectors (1F to 1J) of Embodiment 2 as appropriate. The detector 1K shown in Figures 18A to 18C is, for example, an R-type heat detector. Furthermore, the detector 1K, like the detector 1C of Modified Example 3 in Embodiment 1, does not have a smoke detection unit 4 and is a heat detector that determines the occurrence of fire, etc., solely by detecting heat. Also, the detector 1K, like the detector 1H of Modified Example 2 in Embodiment 2, is equipped with multiple sets of shielding units V1.

[0163] The opening 7 of the sensor 1K according to this embodiment has an inlet 7B, similar to the sensor 1C (see Figures 8A and 8B) and sensor 1D (see Figures 9A and 9B) described in Embodiment 1. In other words, the opening 7 has an inlet 7B in addition to the six side openings (horizontal holes) 7A. The inlet 7B is provided on the outer surface 53 (the lower surface of the front cover 51) of the housing 5, on the side opposite to 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.

[0164] In the sensor 1K, as shown in Figure 18B, a portion of the substrate 2 is exposed from the inlet 7B. Specifically, the substrate 2 has a hole 25 that penetrates through the thickness direction in its center. The hole 25 has a substantially circular opening. The hole 25 is positioned to roughly overlap with the inlet 7B. The substrate 2 has a pair of protrusions 26 that project outwards from the opening edge of the hole 25, approaching each other. The tips of the pair of protrusions 26 are exposed from the inlet 7B. Furthermore, a thermal sensing element 30 (chip thermistor) is also provided on the upper surface of each protrusion 26 of the substrate 2. In short, the sensor 1K has multiple thermal sensing elements 30 (six in the illustrated example) provided near the side opening (horizontal hole) 7A, as well as two thermal sensing elements 30 near the inlet 7B. Furthermore, the substrate 2 has substantially triangular through-holes 31 in the vicinity of each heat sensing element 30 to prevent heat from the heat sensing element 30 from being transferred to the substrate 2 and causing the temperature of the heat sensing element 30 to drop.

[0165] The opening 7 of the sensor 1K has an inlet 7B, which allows it to detect the heat of the gas flowing in from the inlet 7B, thereby improving the responsiveness of heat detection.

[0166] In this embodiment, the outer surface 53 of the sensor 1K 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 Figure 18C, the first surface 531 is tapered at a different angle of inclination than the second surface 532, and approaches the inlet 7B in a direction that moves closer to the structure X1 (upward). As an example, the outer surface 53 further has a third surface 533. The third surface 533 is outside the first surface 531 and inside the second surface 532. When the outer surface 53 is viewed from the front, the first to third surfaces 531 and third surfaces 533 all have a donut shape. Regarding the radial dimensions of the outer surface 53, for example, the second surface 532 is the largest, followed by the third surface 533, and the first surface 531 is the smallest, but this is not particularly limited.

[0167] 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°.

[0168] As described above, in the detector 1K according to this embodiment, the outer surface 53 has a first surface 531 and a second surface 532, so when a fire occurs, the inflow of heat into the inlet 7B can be further promoted (see arrow in Figure 18C). In particular, in the detector 1K, the outer surface 53 is sloped in two stages, including the third surface 533, so the inflow of heat into the inlet 7B can be promoted more effectively.

[0169] Incidentally, periodic inspections to determine whether or not these types of sensors are functioning correctly are mandated by law (for example, every six months). As shown in Figure 19A, the inspector 600 uses a designated (heating) tester 900 to perform a heating test on the heat sensing element 30 of the sensor 1K installed on the structure X1 (the ceiling in the illustrated example).

[0170] The test device 900 includes a heat source 910 such as a Hakkin hand warmer, a main body 920 which is roughly cylindrical with an open top and houses the heat source 910 inside, and a support rod 930 which supports the main body 920. During inspection, the main body 920 is positioned to cover the base 511 and opening 7 of the front cover 51 of the detector 1K from below. If the heat detection element 30 and other components are functioning correctly, the detector 1K will receive heat from the heat source 910 and operate in the same way as if a fire had been detected.

[0171] As explained in Embodiment 1, the fact that the thermal sensing element 30 is a chip thermistor mounted on the substrate 2 allows for miniaturization (especially thinning) of the entire sensor (1, 1A~1K). On the other hand, with the miniaturization of the sensor, there is a possibility that the stability of the position of the test device 900 relative to the sensor may be compromised during inspection.

[0172] Therefore, the housing 5 of the sensor 1K according to this embodiment has a plurality (for example, six) of protrusions W1 (see Figures 18A and 18B; however, only four are shown in Figure 18A). The plurality of protrusions W1 project from the edge of the opening 7 (in this case, the upper edge) in a direction away from the side of the structure X1 to which the sensor 1K is attached (for example, downward). The plurality of protrusions W1 are arranged at equal intervals along the circumferential direction of the housing 5, for example when viewed from below.

[0173] The multiple protrusions W1 are configured to contact the peripheral edge 901 (see Figure 19B) of the test device 900 (see Figure 19B) when the test device 900 for performing a heating inspection of the heat sensing element 30 is positioned to cover the housing 5. The presence of multiple protrusions W1 in this manner ensures that the test device 900 is stably positioned relative to the housing 5. In other words, the likelihood of the protrusions W1 making point contact with the peripheral edge 901 increases, and rattling can be suppressed compared to the case where the housing 5 makes surface contact with the peripheral edge 901 without the presence of the protrusions W1.

[0174] Here, multiple protrusions W1 project downward from the periphery of the lower end of the cylindrical body 510. The multiple protrusions W1 are located at the same position along the circumferential direction of the housing 5, corresponding one-to-one with each of the multiple struts 512. Specifically, each protrusion W1 is formed integrally with a part (upper part) of the corresponding strut 512. In other words, each protrusion W1 also functions as a reinforcing part of the corresponding strut 512. However, each protrusion W1 does not necessarily have to function as a reinforcing part of the strut 512. Each protrusion W1 may be located offset from the struts 512 in the circumferential direction of the housing 5.

[0175] The number of protrusions W1 is not particularly limited; for example, there may be just one. Even with only one protrusion W1, the housing 5 can be positioned more stably than when it is in surface contact with the peripheral edge 901 of the test device 900.

[0176] Figure 20 also shows a modified sensor 1L of Embodiment 3. This modified sensor 1L also has a first surface 531 whose outer surface 53 is tapered. Sensor 1L is, for example, a P-type heat detector. In particular, sensor 1L, like sensor 1G of Modification 1 of Embodiment 2, has two sets of shielding sections 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 set of the two sets of shielding sections V1 is shown, and the remaining set of shielding sections V1 is located on the back side.

[0177] Furthermore, the sensor 1L has a plurality (for example, four) of protrusions W1 configured to contact the peripheral edge 901 of the test device 900 (see Figure 19B) (see Figure 20; however, only three are shown). Here, at least one of the four protrusions W1 is formed integrally with a part (upper part) of the second column V13, so as to function as a reinforcing part of the second column V13 in the middle of the shielding part V1. In short, the four protrusions W1 of the sensor 1L are located along the circumferential direction of the housing 5, in the same positions as the two struts 512 and the two second columns V13 (including the second column V13 of the shielding part V1 on the opposite side of the illustrated shielding part V1), with a one-to-one correspondence to each of them.

[0178] (Embodiment 4) The detector 1M according to this embodiment will be described below with reference to Figures 21A and 21B. Hereafter, components substantially similar to those in Embodiment 1 will be denoted by common reference numerals, and their descriptions will be omitted as appropriate. The detector 1M shown in Figures 21A and 21B is, for example, an R-type heat detector. Furthermore, like the detector 1C in Modification 3 of Embodiment 1, the detector 1M does not have a smoke detection unit 4 and is a heat detector that determines the occurrence of a fire, etc., solely by detecting heat. The detector 1M also includes multiple sets of shielding units V1, each having three columns.

[0179] The detector 1M further includes a mounting base 100B for installing its main body 100A on the structure X1 (the ceiling in the illustrated example). The mounting base 100B may also be appropriately applied to the detectors of Embodiment 1 (1, 1A~1E), the detectors of Embodiment 2 (1F~1J), or Embodiment 3 (1K, 1L).

[0180] The mounting base 100B is formed in a flat cylindrical shape with an open bottom. The mounting base 100B is fixed to the surface of the structure X1 by screws or the like. The structure X1 is provided with holes for routing electrical wires (power supply wires, signal wires, etc.) on its back side. The mounting base 100B has a through hole 103 (see Figure 21B) at its bottom 106 for routing the electrical wires routed from the holes in the structure X1 toward the main body 100A.

[0181] The mounting base 100B also has an outer peripheral wall 104 and a flange portion 105 that protrudes outward from the outer peripheral wall 104. The outer peripheral wall 104 is configured to fit into a recess formed by the cylindrical body 510 and the back cover 52 (see Figure 1) on the upper side of the main body 100A. Although a detailed explanation is omitted, for example, by rotating the outer peripheral wall 104 in the recess of the main body 100A clockwise with respect to the axial direction, an engaged portion of the mounting base 100B is provided which engages with the engaging portion of the back cover 52. The main body 100A is fixed to the mounting base 100B when the engaging portion of the back cover 52 engages with the engaged portion.

[0182] As shown in Figure 21A, when the main body 100A of the sensor 1M is fixed to the mounting base 100B, the outer surface of the flange portion 105 and the outer surface of the cylindrical body 510 are substantially flush, thus providing a sensor with an aesthetically pleasing appearance.

[0183] Incidentally, the mounting base 100B described above is a base unit of the type that directly mounts the sensor 1M to 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 equipped with a recessed base 100C, as shown in Figures 22A and 22B. The recessed base 100C is a base unit of the type that embeds the sensor 1M into the structure X1.

[0184] The embedded base 100C includes a base body 107 that is inserted into an embedded hole in the structure X1, and a decorative part 108 that is formed integrally with the base body 107.

[0185] The base body 107 is formed in a flat cylindrical shape with an open bottom. The embedded base 100C also has, for example, a mounting bracket (the first mounting bracket T1 or the second mounting bracket T2 described later) for fixing to the structure X1 when inserted into the hole in the structure X1. The base body 107 has a through hole 110 (see Figure 22B) at its bottom 109 for passing the electric wires on the back side of the structure X1 toward the main body 100A.

[0186] The base body 107 has a recess 111 with an inner diameter slightly larger than the outer diameter of the main body 100A. That is, the main body 100A can be accommodated within 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.

[0187] The decorative part 108 protrudes outward in a flange-like manner from the lower end of the base body 107. The decorative part 108 is exposed below the surface of the structure X1 when the base body 107 is inserted into the hole in the structure X1.

[0188] While a detailed explanation is omitted, for example, when the main body 100A is fitted into the recess 111 of the base body 107, rotating it clockwise in the axial direction causes the engaged portion of the back cover 52 to engage with the engaged portion, which is provided on the embedded base 100C. The main body 100A is fixed to the embedded base 100C when the engaged portion of the back cover 52 engages with the engaged portion.

[0189] As shown in Figure 22A, when the main body 100A of the sensor 1M is fixed to the embedded base 100C, the amount of protrusion from the surface of the structure X1 can be reduced, thus providing a sensor with an aesthetically pleasing appearance.

[0190] Here, the mounting method for attaching the embedded base 100C to the structure X1 using a pair of first mounting brackets T1 will be explained with reference to Figure 23A. The embedded base 100C has a pair of first mounting brackets T1. In Figure 23A, for the sake of explanation, only the structure X1 is shown in cross-section. Each first mounting bracket T1 has a fixing screw T11 and a partially bent leaf spring-shaped fixing piece T12. The fixing piece T12 has a screw hole into which the fixing screw T11 is screwed. The fixing piece T12 is temporarily 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 part T120 of the fixing piece T12 and the head of the fixing screw T11.

[0191] When attaching the embedded base 100C to the structure X1, first loosen each fixing screw T11 with a screwdriver or other tool to release the clamped state described above. In this state, each fixing piece T12 can be tilted inward together with the fixing screw T11 (see dashed lines in Figure 23A). Tilt each fixing piece T12 inward and, while maintaining that state, insert the base body 107 into the hole X11 of the structure X1. Then, by tightening each fixing screw T11 with a screwdriver or other tool, the fixing piece T12 tilts outward with the flat part T120 in contact with the base body 107 as the pivot point, and its tip T121 (point of application) comes into contact with the back surface of the structure X1. Then, by further tightening each fixing screw T11, the structure X1 is clamped vertically by the tips T121 of each fixing piece T12 and the decorative part 108, and as a result, the embedded base 100C is fixed to the structure X1.

[0192] Next, the mounting method for attaching the embedded base 100C to the structure X1 using a pair of second mounting brackets T2 will be explained with reference to Figure 23B. The embedded base 100C has a pair of second mounting brackets T2. In Figure 23B, for the sake of explanation, only the structure X1 is shown 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 temporarily fixed to the fixing screw T21 on the upper side of the decorative part 108, with the fixing screw T21 inserted from below into the through hole in the decorative part 108.

[0193] When attaching the embedded base 100C to the structure X1, first loosen each fixing screw T21 with a screwdriver or other tool and rotate the fixing piece T22 so that the tip faces inward. While maintaining this state, insert the base body 107 into the hole X11 of the structure X1. Then, by tightening each fixing screw T21 with a screwdriver or other tool, the tip of the fixing piece T22 faces outward, and the fixing piece T22 descends toward the back surface of the structure X1, making general surface contact. Then, by further tightening each fixing screw T21, the structure X1 is sandwiched vertically between each fixing piece T22 and the decorative part 108, and as a result, the embedded base 100C is fixed to the structure X1.

[0194] 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. Similarly, the mounting method described above is merely an example and is not limited to these.

[0195] (4) Summary As described above, the sensor (1, 1A~1M) according to the first embodiment comprises a substrate (2), a thermal sensing element (30), and a housing (5). The housing (5) houses the substrate (2). The housing (5) has a flow path (6) through which gas flows, provided in its internal space (SP1), and an opening (7) connecting the flow path (6) to the external space (SP2) of the housing (5). The thermal sensing element (30) is a chip thermistor mounted on the substrate (2) that detects the heat of gas flowing in through the opening (7). According to the first embodiment, since the thermal sensing element (30) is a chip thermistor mounted on the substrate (2), the overall size of the sensor (1, 1A~1M) can be reduced.

[0196] With respect to the sensors (1, 1A to 1M) according to the second embodiment, in the first embodiment, it is preferable that at least a portion of the surface of the substrate (2) (for example, the first surface 21) is exposed to the flow path (6). According to the second embodiment, the possibility of the heat sensing element (30) being exposed to the gas flowing through the flow path (6) can be increased, thereby improving the heat detection performance while achieving miniaturization.

[0197] With respect to the sensors (1, 1A~1M) according to the third embodiment, in the first or second embodiment, it is preferable that the chip thermistor is positioned so as to be contained within the opening region (70) when viewed from the external space (SP2) side of the opening region (70). According to the third embodiment, the possibility of the heat sensing element (30) being exposed to the gas flowing through the flow path (6) can be increased, thereby improving heat detection performance while achieving miniaturization.

[0198] With respect to the sensors (1, 1A~1M) according to the fourth embodiment, in the third embodiment, the chip thermistor is preferably located in the following position. That is, when the opening region (70) is viewed from the side of the external space (SP2), the chip thermistor is preferably located in the center of the opening region (70) in a direction perpendicular to the surface of the substrate (2) (for example, the first surface 21). According to the fourth embodiment, for example, the possibility of the heat sensing element (30) being exposed to the gas flowing through the flow path (6) can be further increased compared to the case where the chip thermistor is located closer to one end of the opening region (70) in the above direction.

[0199] With respect to the sensor (1, 1A~1M) according to the fifth embodiment, in any one of the first to fourth embodiments, the flow path (6) includes a first path (61) located on the side of the opening (7) and a second path (62) connected to the first path (61) and located on the side of the central part of the internal space (SP1). It is preferable that the chip thermistor is located in the first path (61). According to the fifth embodiment, for example, the responsiveness with respect to heat detection can be improved compared to the case where the chip thermistor is located in the second path (62).

[0200] With respect to the sensor (1, 1A~1M) according to the sixth embodiment, in any one of the first to fifth embodiments, the flow path (6) includes a first path (61) located on the side of the opening (7) and a second path (62) connected to the first path (61) and located on the side of the central part of the internal space (SP1). Preferably, 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 embodiment, gas that enters the flow path (6) through the opening (7) can be promoted to flow from the first path (61) towards the second path (62).

[0201] With respect to the sensors (1, 1A~1M) according to the seventh embodiment, in the sixth embodiment, it is preferable that the housing (5) has an installation surface (55) facing the structure (X1) to which the sensors (1, 1A~1M) are attached. It is preferable that the second path (62) widens in a direction that approaches the installation surface (55) as it moves from the first path (61) toward the central part. According to the seventh embodiment, it is possible to generate airflow more effectively from the first path (61) toward the second path (62).

[0202] The detector (1, 1A~1M) according to the eighth embodiment preferably further comprises a smoke detection unit (4) which is located in the center of the internal space (SP1) and detects smoke, in any one of the first to seventh embodiments. According to the eighth embodiment, since it detects not only heat but also smoke, it is possible to improve fire detection performance while making the detector (1, 1A~1M) as a whole smaller.

[0203] With respect to the detectors (1, 1A to 1M) according to the ninth embodiment, in the eighth embodiment, it is preferable that the smoke detection unit (4) is located 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 embodiment, it is possible to further improve the fire detection performance while miniaturizing the detectors (1, 1A to 1M) as a whole.

[0204] With respect to the detectors (1, 1A~1M) according to the tenth embodiment, in the eighth or ninth embodiment, it is preferable that the housing (5) has an installation surface (55) facing the structure (X1) to which the detectors (1, 1A~1M) are attached. It is preferable that the smoke detection unit (4) is arranged on the surface of the substrate (2) that is closer to the installation surface (55), between the surface (e.g., the first surface 21) and the surface opposite to the surface (e.g., the second surface 22). According to the tenth embodiment, for example, it is possible to further reduce the size compared to the case where the smoke detection unit (4) is arranged on the surface that is farther from the installation surface (55).

[0205] With respect to the detectors (1, 1A~1M) according to the 11th embodiment, in any one of the 8th to 10th embodiments, 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 unit (4). According to the 11th embodiment, the fire detection performance can be further improved.

[0206] With respect to the detectors (1, 1A~1M) according to the 12th embodiment, in any one of the 8th to 11th embodiments, it is preferable that the housing (5) has an installation surface (55) facing the structure (X1) to which the detectors (1, 1A~1M) are attached. The smoke detection unit (4) includes an optical element (41) that emits light, a light-receiving element (42) that receives light emitted from the optical element (41), and a labyrinth section (43). Within the labyrinth section (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 section (43) is between the chip thermistor and the installation surface (55). According to the twelfth embodiment, in a detector (1, 1A~1M) that detects not only heat but also smoke, it is possible to further improve the fire detection performance while miniaturizing the detector (1, 1A~1M) as a whole.

[0207] With respect to the sensor (1, 1A~1M) according to the 13th embodiment, in any one of the 1st to 12th embodiments, it is preferable that the chip thermistor is positioned so that it fits within the opening region (70) when viewed from the external space (SP2) side of the opening region (70). It is preferable that the sensor (1, 1A~1M) further comprises a shielding portion (V1) that obstructs a part of the opening region (70) on the external space (SP2) side of the chip thermistor. According to the 13th embodiment, the shielding portion (V1) makes it less likely for heat to flow in from the opening (7) to be obstructed, while reducing the possibility that, for example, a person's finger or a tool may unintentionally come into contact with the chip thermistor.

[0208] With respect to the sensors (1, 1A~1M) according to the 14th embodiment, in the 13th embodiment, 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 embodiment, the possibility that the shielding portion (V1) will obstruct the inflow of heat from the opening (7) can be further reduced.

[0209] With respect to the sensor (1, 1A~1M) according to the 15th embodiment, in the 13th or 14th embodiment, it is preferable that the housing (5) has a first cover (for example, one of a front cover 51 and a 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 direction opposite to the above-mentioned direction in the thickness direction. It is preferable that the shielding portion (V1) has a first projection (V14, V16) protruding from the first cover toward the second cover and a second projection (V15, V17) protruding from the second cover toward the first cover. According to the 15th embodiment, it is possible to further reduce the possibility of a person's finger or tool coming into contact with the chip thermistor while making it less likely for heat to be obstructed from the opening (7).

[0210] With respect to the detectors (1, 1A~1M) according to the 16th embodiment, in the 15th embodiment, the first projection (V14) is preferably arranged as follows: That is, when viewing the opening region (70) from the side of the external space (SP2), the first projection (V14) is preferably offset from the second projection (V15) in a direction perpendicular to the direction in which the first cover and the second cover are aligned. According to the 16th embodiment, the possibility that the shielding portion (V1) will obstruct the inflow of heat from the opening (7) can be further reduced.

[0211] With respect to the sensor (1, 1A~1M) according to the 17th embodiment, in the 15th embodiment, it is preferable that the first projection (V16) and the second projection (V17) protrude so that their tips face each other. According to the 17th embodiment, the possibility of a person's finger or tool coming into contact with the chip thermistor can be further reduced.

[0212] With respect to the sensor (1, 1A~1M) according to the 18th embodiment, in any one of the 15th to 17th embodiments, it is preferable that at least one of the first projections (V14, V16) and the second projections (V15, V17) (here, the second projection V15) is as follows: That is, it is preferable that the at least one is in the same position as the chip thermistor in a direction perpendicular to the direction in which the first cover and the second cover are aligned when the opening region (70) is viewed from the side of the external space (SP2). Furthermore, it is preferable that the amount of protrusion of the at least one is defined such that at least a part of the chip thermistor is exposed when the opening region (70) is viewed from the side of the external space (SP2). According to the 18th embodiment, it is possible to further reduce the possibility of a person's finger or tool coming into contact with the chip thermistor while making it less likely for heat to flow in from the opening (7) to be obstructed.

[0213] With respect to the detectors (1, 1A~1M) according to the 19th embodiment, in any one of the 1st to 18th embodiments, 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) opposite to the structure (X1) to which the detectors (1, 1A~1M) are attached. According to the 19th embodiment, the heat of the gas flowing in from the inlet (7B) can be detected, thereby improving the responsiveness to heat detection.

[0214] With respect to the detectors (1, 1A~1M) according to the 20th embodiment, in the 19th embodiment, 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 a different angle of inclination than the second surface (532) and approaches the structure (X1) as it approaches the inlet (7B). According to the 20th embodiment, heat inflow into the inlet (7B) can be further promoted.

[0215] With respect to the detectors (1, 1A~1M) according to the 21st embodiment, in any one of the 1st to 20th embodiments, it is preferable that the housing (5) has one or more protrusions (W1). The one or more protrusions (W1) project from the edge of the opening (7) in a direction away from the side of the structure (X1) to which the detectors (1, 1A~1M) are attached. It is preferable that the one or more protrusions (W1) are configured to contact the peripheral edge (901) of the test device (900) when the test device (900) for performing a heating inspection of the heat sensing element (30) is positioned so as to cover the housing (5). According to the 21st embodiment, the presence of the protrusions (W1) allows the test device (900) to be stably positioned relative to the housing (5). That is, the possibility of the protrusions (W1) making point contact with the peripheral edge (901) increases, and rattling can be suppressed compared to surface contact.

[0216] The configurations relating to the second to twelfth aspects are not essential for the detectors (1, 1A to 1E) and can be omitted as appropriate. [Explanation of Symbols]

[0217] 1, 1A~1M sensor 2 circuit boards 30 Thermal sensing elements 4. Smoke detection unit 41 Optical elements 42 Photodetector 43 Labyrinth Section 5 cabinets 51 Front cover (second cover) 52 Back cover (first cover) 53 Outer surface 531 1st surface 532 2nd surface 55 Installation surface 522 Control panel (wall) 6 channels 61 Route 1 62 2nd road 7 Opening 7B Inlet 70 aperture area P1 center SP1 interior space SP2 External space V1 shielding part V14, V16 1st protrusion V15, V17 2nd protrusion V2 induction surface W1 protrusion X1 structure 900 Testing Equipment 901 Peripheral area

Claims

1. circuit board and A heat sensing element, A housing for the aforementioned circuit board, Equipped with, The aforementioned substrate is The main body and The edge of the main body portion has an extension portion that extends in a direction away from the center of the main body portion, The heat sensing element is arranged in the extension portion. sensor.

2. The substrate has a plurality of extensions, The plurality of extensions include one or more pairs of extensions that extend in directions away from each other at the edge of the main body. The detector according to claim 1.

3. The device further comprises a display unit that notifies the operating status of the sensor to the outside, The display unit has a light source, In addition to the first extension portion which is the extension portion, the substrate has a second extension portion which extends from the edge of the main body portion in a direction away from the center of the main body portion. The light source is located in the second extension. The detector according to claim 1 or 2.

4. The extension amount of the second extension is less than the extension amount of the first extension. The detector according to claim 3.

5. The extension portion has a narrow small piece at its tip, The heat sensing element is located in the small piece portion. A detector according to any one of claims 1 to 4.

6. The extension portion is provided with a through hole, The heat sensing element is located near the through hole. A detector according to any one of claims 1 to 5.

7. The through hole is located inside the heat sensing element, The detector according to claim 6.

8. The opening area of ​​the through hole, when viewed from above the substrate, is larger than the surface area of ​​the heat sensing element. The detector according to claim 6 or 7.

9. The thermal sensing element is a chip thermistor. A detector according to any one of claims 1 to 8.

10. The housing has a smoke detection unit for detecting smoke, A detector according to any one of claims 1 to 9.

11. An automatic fire alarm system comprising a detector according to any one of claims 1 to 10 and a receiver that communicates with the detector.

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