Patent Description:
<CIT> discloses a smoke and heat sensor. The smoke and heat sensor includes a heat sensing means for sensing heat and a smoke sensing unit for sensing smoke that has flowed into a dark box. The smoke and heat sensor houses, inside a housing including a body base and a body case covering an upper part of the body base, a circuit board mounted on the upper surface of the body base, the heat sensing means, and the smoke sensing unit. The heat sensing means includes a plurality of heat sensors provided beside the dark box.

<CIT> describes a sensor comprising: a substrate; at least one of heat detection elements mounted on the substrate; a housing for storing the substrate; and an air flow formation part. The housing includes: a flow passage arranged in inner spaces of the housing so as to allow a gaseous matter to flow; openings connecting the flow passage to an outer space of the housing; and an arrangement surface to be opposed to a structure body when the housing is attached to the structure body. The openings include a flow-in port arranged in an outer surface on the opposite side of the arrangement surface in the housing. The air flow formation part is constituted to form an air flow by allowing a gaseous matter flown from the flow-in port to flow toward the heat detection elements.

There has been an increasing demand for further improving the thermal response of such a sensor that detects the presence of fire by heat.

In view of the foregoing background, it is therefore an object of the present disclosure to provide a sensor contributing to improving the thermal response. This objective is achieved by the independent claim. Particular embodiments are defined in the dependent claims.

A sensor according to an aspect of the present disclosure includes a board, a heat detecting element, a housing, and a heat collector. The heat detecting element is mounted on the board and detects heat. The housing houses the board. The housing has a flow channel and an opening. The flow channel is provided in an internal space of the housing and allows air to flow therethrough. The opening allows the flow channel to communicate with an external space outside of the housing. The heat collector is configured to collect hot air toward the heat detecting element.

Note that the embodiments and their variations to be described below are only exemplary embodiments of the present disclosure and their variations and should not be construed as limiting. Rather, the exemplary embodiments and their variations may be readily modified in various manners depending on a design choice or any other factor without departing from the scope of the present disclosure. The invention is defined by the features as claimed in claim <NUM>.

A sensor <NUM> according to a first embodiment will be described with reference to <FIG>.

A sensor <NUM> according to a first embodiment may be implemented as, for example, a fire sensor. In the first embodiment, the sensor <NUM> is supposed to be, for example, a smoke and heat sensor having both the capability of detecting heat generated by a fire, for example, and the capability of detecting smoke produced by a fire, for example. Nevertheless, the sensor <NUM> does not have to be a smoke and heat sensor and does not have to have the capability of detecting smoke. The sensor <NUM> is installed on a ceiling surface of a building as shown in <FIG>.

As shown in <FIG>, the sensor <NUM> according to the first embodiment includes a board <NUM>, at least one heat detecting element <NUM>, a housing <NUM>, and at least one heat collector <NUM>.

The at least one heat detecting element <NUM> is mounted on the board <NUM> to detect heat. In the first embodiment, the heat detecting element <NUM> may be implemented as, for example, a chip thermistor. The heat detecting element <NUM> is disposed under the board <NUM>.

The housing <NUM> houses the board <NUM>. The housing <NUM> has: a flow channel <NUM> (see <FIG>) provided in an internal space SP1 of the housing <NUM> and allowingair to flow therethrough; and at least one opening <NUM> allowing the flow channel <NUM> to communicate with an external space SP2 (see <FIG>) outside of the housing <NUM>.

The at least one heat collector <NUM> is configured to collect hot air toward the heat detecting element <NUM>. The heat collector <NUM> is formed integrally with a lower cover <NUM> of the housing <NUM>.

This configuration includes the heat collector <NUM>, thus achieving the following advantage. Specifically, the hot air flowing into the internal space SP1 of the sensor <NUM> through the opening <NUM> flows along the flow channel <NUM> to reach the heat detecting element <NUM>. As a result, the sensor <NUM> detects heat. In this case, a gas flow with heat (hereinafter referred to as "hot air") is collected by the heat collector <NUM> to wrap the heat detecting element <NUM> mounted on the board <NUM> and their surroundings, thus causing the heat detecting element <NUM> to be heated rapidly. Therefore, the heat collector <NUM> increases the heat detecting rate. Consequently, the sensor <NUM> achieves the advantage of improving the thermal response.

Meanwhile, when a test is conducted using a heater-type heating tester <NUM> (see <FIG>), the heat source thereof is a localized one compared to a fire, and therefore, the test result tends to be affected by respective heights of the heat source H10 of the heating tester <NUM> and the height of the board of the sensor. Particularly when the height of the heat source of the heating tester <NUM> disagrees with the height of the board of the sensor, the hot air does not enter the sensor smoothly, thus causing a decline in thermal response and taking a lot of time to have a test using the heating tester <NUM> done. In contrast, the sensor <NUM> according to the first embodiment includes the heat collector <NUM>, thus improving the thermal response not only to the actual presence of a fire but also to the heating tester <NUM> as well. This achieves the advantage of having the test using the heating tester <NUM> done in a shorter time.

Next, an overall configuration for the sensor <NUM> according to the first embodiment will be described in detail. As described above, the sensor <NUM> may be, for example, a smoke and heat sensor for detecting both smoke and heat.

In the following description, the vertical arrangement of respective members of the sensor <NUM> will be described by using the up and down arrows shown in <FIG>, illustrating a state where the sensor <NUM> is installed on a ceiling surface). Note that these arrows are shown there as just an assistant to description and are insubstantial ones. In addition, these arrows should not be construed as limiting the directions in which the sensor <NUM> is used.

As shown in <FIG> and <FIG>, the sensor <NUM> includes the board <NUM>, a heat detector <NUM> including a single or a plurality of heat detecting elements <NUM>, a smoke detector <NUM>, a flow channel forming member <NUM>, the heat collector <NUM>, and the housing <NUM>. In addition, the sensor <NUM> further includes a controller <NUM> and an indicator <NUM> as shown in <FIG>.

The sensor <NUM> further includes a disklike attachment base (not shown) to be fixed with screws, for example, onto the installation surface <NUM>. The sensor <NUM> may be installed onto the installation surface <NUM> by removably attaching an attachment portion, provided on the upper surface of the housing <NUM>, onto the attachment base.

In addition, the sensor <NUM> further includes a communications interface <NUM> (see <FIG>). The communications interface <NUM> transmits, when the sensor <NUM> detects the presence of fire, a signal alerting to the presence of the fire to an external alarm device, for example, and receives a signal from the alarm device.

The sensor <NUM> may be powered by a commercial power supply or a battery provided inside the housing <NUM>, whichever is appropriate.

The housing <NUM> houses the board <NUM>, the heat detector <NUM>, the smoke detector <NUM>, the controller <NUM>, the indicator <NUM>, the communications interface <NUM>, and other circuit modules inside.

The housing <NUM> is made of a synthetic resin and may be made of flame-retardant ABS resin, for example. The housing <NUM> is formed in a vertically compressed cylindrical shape as a whole. As shown in <FIG>, the housing <NUM> includes a cylindrical lower cover <NUM> (front cover), one side (e.g., the upper side in the example shown in <FIG>) of which is open, and a generally disklike upper cover <NUM> (back cover). The housing <NUM> is formed by fitting the upper cover <NUM> into the lower cover <NUM> through one side thereof that is open. The upper cover <NUM> is arranged to cover the smoke detector <NUM> from over the smoke detector <NUM>. The lower cover <NUM> is disposed under the board <NUM>.

The housing <NUM> has a flow channel <NUM> (see <FIG>), which is provided in the internal space SP1 thereof to allow hot air to flow therethrough, and a single or a plurality of (e.g., twelve in this embodiment) openings <NUM> (lateral holes) that allows the flow channel <NUM> to communicate with the external space SP2 outside of the sensor <NUM>. In this embodiment, a plurality of openings <NUM> are provided through the lower cover <NUM>. In other words, the lower cover <NUM> has a plurality of openings <NUM> that allows the internal space SP1 to communicate with the external space SP2.

Specifically, the lower cover <NUM> includes: a bottom member <NUM> that forms the bottom of the openings <NUM>; and a cylindrical upper member <NUM> that forms the side surface of the housing <NUM>. In addition, the lower cover <NUM> further includes a plurality of (e.g., twelve in this embodiment) beams <NUM> that couple the bottom member <NUM> to the upper member <NUM>. The bottom member <NUM>, the upper member <NUM>, and the twelve beams <NUM> are formed integrally with each other. The twelve beams <NUM> are arranged at substantially regular intervals along the circumference A3 on the outer peripheral edge <NUM> of the bottom member <NUM> and protrude from the outer peripheral edge <NUM> toward the opened lower edge portion of the upper member <NUM>. The twelve beams <NUM> are provided to maintain a predetermined gap distance between the upper member <NUM> and the bottom member <NUM>. Twelve openings <NUM> are arranged at substantially regular intervals along the circumference of the peripheral wall with such a configuration (corresponding to the circumference A3 of the sensor <NUM>).

Each of the openings <NUM> is a generally rectangular through hole, which penetrates radially through the peripheral wall of the lower cover <NUM> and allows the flow channel <NUM> to communicate with the external space SP2.

The bottom member <NUM> has, on its upper surface, a positioning structure for positioning the board <NUM>. In this embodiment, a cylindrical portion <NUM> is provided as the positioning structure (see <FIG>). In other words, the sensor <NUM> according to the first embodiment further includes the cylindrical portion <NUM> arranged to cover the lower surface of the board <NUM>. The cylindrical portion <NUM> protrudes from the upper surface of the bottom member <NUM>. The upper end surface of the cylindrical portion <NUM> is in contact with the lower surface of the board <NUM>.

The upper cover <NUM> has, on the lower surface, a plurality of connection pieces <NUM> (see <FIG>) that protrude downward. The plurality of connection pieces <NUM> are respectively inserted into a plurality of insert holes <NUM> (to be described later) provided through the flow channel forming member <NUM> and respectively fitted into a plurality of fitting holes <NUM> provided through the board <NUM>. Inserting the plurality of connection pieces <NUM> into the plurality of insert holes <NUM> of the flow channel forming member <NUM> makes the plurality of connection pieces <NUM> electrically connected to terminals on terminal stages <NUM>, which are arranged adjacent to the insert holes <NUM>. The terminals on the terminal stages <NUM> are electrically connected to circuit modules provided on the board <NUM>. The upper cover <NUM> is mechanically connected to a contact portion of the attachment base fixed to the installation surface <NUM>, thereby making the plurality of connection pieces <NUM> electrically connected to the contact portion. As a result, the circuit modules provided on the board <NUM> are electrically connected to electric cables (including power cables and signal cables) provided on the backside of the ceiling via the terminal stages <NUM>, the connection pieces <NUM>, the contact portion, and other members.

In addition, the upper cover <NUM> further has, on one surface (lower surface) thereof facing the board <NUM>, a housing recess <NUM> (see <FIG>) to house an upper portion of the smoke detector <NUM> mounted on the board <NUM>. The housing recess <NUM> is formed by making the entire central portion of the upper cover <NUM> protrude upward. The smoke detector <NUM> may be positioned stably by the housing recess <NUM>.

In this embodiment, the sensor <NUM> further includes gas flow control walls <NUM> as shown in <FIG>. In this embodiment, the gas flow control walls <NUM> may form integral parts of the upper cover <NUM>, for example. The three gas flow control walls <NUM> are provided on one surface (lower surface), facing the board <NUM>, of the upper cover <NUM> to be located outward of the housing recess <NUM>. In the first embodiment, the three gas flow control walls <NUM> are arranged around the smoke detector <NUM> to reduce non-uniformity in smoke flowability along the circumference A3 of, and with respect to, the smoke detector <NUM>.

The board <NUM> is configured to mount the smoke detector <NUM> thereon. In this embodiment, the board <NUM> may be implemented as, for example, a circuit board. The board <NUM> may be, for example, a single printed wiring board on which patterned conductor wiring is formed. The board <NUM> has a pair of engagement holes, which penetrate through the board <NUM> in the thickness direction. The smoke detector <NUM> is mounted onto the upper surface of the board <NUM>. In addition, the flow channel forming member <NUM> is also held by the board <NUM> as will be described later.

On the board <NUM>, not only the smoke detector <NUM> but also the heat detector <NUM>, the controller <NUM>, the indicator <NUM>, the communications interface <NUM>, and other circuit modules are mounted as well. Examples of the other circuit modules include a lighting circuit for turning ON a light source for the indicator <NUM> and an optical element <NUM> (see <FIG>) of the smoke detector <NUM> and a power supply circuit for generating operating power for various types of circuits based on the power supplied from a commercial power supply, for example.

As shown in <FIG> and <FIG>, the board <NUM> is formed in a generally disklike shape as a whole. In the first embodiment, the heat detector <NUM> includes a single or a plurality of (e.g., six in this embodiment) heat detecting elements <NUM> and the six heat detecting elements <NUM> are arranged along an outer peripheral portion <NUM> of the board <NUM>. The six heat detecting elements <NUM> are surface-mounted on the lower surface <NUM> of the board <NUM>. Meanwhile, the smoke detector <NUM> is mounted on the upper surface <NUM> of the board <NUM>.

The controller <NUM> and a plurality of electronic components forming circuit modules may be mounted on the upper surface <NUM> or lower surface <NUM> of the board <NUM>. However, the controller <NUM> and a plurality of electronic components forming circuit modules do not have to be mounted only on the board <NUM>. Alternatively, another mount board may be provided around the board <NUM> and some or all of the controller <NUM> and the electronic components may be mounted on the mount board.

Next, the structure of the board <NUM> will be described in detail. As shown in <FIG>, the board <NUM> includes a disklike body <NUM> and a plurality of (e.g., six in the first embodiment) extended portions extended from the edge of the body <NUM> to go away from the center of the body <NUM>. The smoke detector <NUM> is disposed in a central area of the upper surface of the body <NUM>.

These six extended portions are configured as six tongue portions <NUM>. Each of the tongue portions <NUM> is a portion on which an associated heat detecting element <NUM> out of the six heat detecting elements <NUM> is mounted. Each of the tongue portions <NUM> has an upper surface and a lower surface, which are respectively flush with the upper surface and lower surface of the body <NUM>. When viewed in the upward/downward direction, each of the tongue portions <NUM> protrudes as an elongate strip plate from the body <NUM> and has a semicircular tip portion. These six tongue portions <NUM> are arranged at regular intervals along the circumference A3 of the body <NUM> to divide the outer peripheral portion <NUM> of the board <NUM> into six approximately evenly. Each of the heat detecting elements <NUM> is mounted on the lower surface of an associated one of the tongue portions <NUM> to be located around the tip portion thereof. Each of the tongue portions <NUM> has a through hole <NUM> having a rectangular opening inside of its associated heat detecting element <NUM>. Providing the through hole <NUM> beside each heat detecting element <NUM> may reduce the area of the board <NUM> around the heat detecting element <NUM>. This may reduce the chances of the heat of the heat detecting element <NUM> being transmitted through the board <NUM> to cause some heat loss or the heat generated by other circuit components mounted on the body <NUM> affecting the heat detecting element <NUM>. That is to say, the through hole <NUM> improves the thermal insulation properties. The opening area of the through hole <NUM> is preferably larger than the surface area of the heat detecting element <NUM> (e.g., the surface area thereof when viewed from over the board <NUM>).

As described above, the heat detector <NUM> includes the six heat detecting elements <NUM> which are mounted on the lower surface <NUM> of the board <NUM>. Note that the six heat detecting elements <NUM> are shown as a single block in <FIG>. The number of the heat detecting elements <NUM> provided is not limited to any particular number but may also be one. Nevertheless, at least two heat detecting elements <NUM> are suitably provided. In addition, each heat detecting element <NUM> detects the heat of the hot air that has flowed in through the opening <NUM> and is surface-mounted on the board <NUM>. In the first embodiment, the heat detecting elements <NUM> may be implemented as, for example, chip thermistors. Also, in the first embodiment, when viewed along the radius of the lower cover <NUM>, each heat detecting element <NUM> is provided between two adjacent openings <NUM> out of the plurality of openings <NUM>.

The heat detector <NUM> is electrically connected, via patterned wiring formed on the board <NUM> and other members, to the controller <NUM>. Each heat detecting element <NUM> outputs an electrical signal (detection signal) to the controller <NUM>. In other words, the controller <NUM> monitors, based on the electrical signals provided by the respective heat detecting elements <NUM>, the resistance values, which may vary as the temperature increases, of the respective heat detecting elements <NUM>.

Optionally, the heat detectors <NUM> may include not only the heat detecting elements <NUM> but also an amplifier circuit for amplifying the electrical signals provided by the heat detecting elements <NUM>, a converter circuit for performing analog-to-digital conversion on the electrical signals, and other circuits as well. Alternatively, the amplification and analog-to-digital conversion of the electrical signals provided by the heat detecting elements <NUM> may be performed by the circuit modules.

The smoke detector <NUM> is provided in a central area of the internal space SP1 of the housing <NUM> and configured to detect smoke. Specifically, the smoke detector <NUM> is disposed on the upper surface of the body <NUM> of the board <NUM> and has an upper portion thereof housed in the housing recess <NUM> of the upper cover <NUM>. The smoke detector <NUM> may be a photoelectric sensor for detecting smoke, for example, and may be a scattering light type sensor, in particular.

As shown in <FIG>, the smoke detector <NUM> includes an optical element <NUM> for emitting light, a photosensitive element <NUM> for receiving the light emitted from the optical element <NUM>, and a labyrinth structure <NUM>. The optical element <NUM> may be a light-emitting diode (LED), for example. The photosensitive element <NUM> may be a photodiode, for example. The labyrinth structure <NUM> is formed inside a housing having a compressed, generally circular cylindrical shell.

The optical element <NUM> and the photosensitive element <NUM> are arranged inside the labyrinth structure <NUM> to avoid facing each other. In other words, the optical element <NUM> and the photosensitive element <NUM> are arranged such that the photosensitive plane of the photosensitive element <NUM> is off the optical axis of the light emitted from the optical element <NUM>.

At the outbreak of a fire, for example, smoke involved with the fire may enter the housing <NUM> through the openings <NUM> of the housing <NUM> and be introduced into the labyrinth structure <NUM> through an inlet port. If no smoke is present in the labyrinth structure <NUM>, the light emitted from the optical element <NUM> hardly reaches the photosensitive plane of the photosensitive element <NUM>. On the other hand, if there is any smoke in the labyrinth structure <NUM>, then the light emitted from the optical element <NUM> is scattered by the smoke and part of the scattered light eventually impinges on the photosensitive plane of the photosensitive element <NUM>. That is to say, the smoke detector <NUM> makes the photosensitive element <NUM> receive the light that been emitted from the optical element <NUM> and scattered by the smoke.

The photosensitive element <NUM> of the smoke detector <NUM> is electrically connected to the controller <NUM>. The smoke detector <NUM> transmits an electrical signal (detection signal), having a voltage level representing the quantity of light received at the photosensitive element <NUM>, to the controller <NUM>. In response, the controller <NUM> converts the quantity of the light, represented by the detection signal provided by the smoke detector <NUM>, into a smoke concentration, thereby determining whether or not a fire is actually present. Optionally, the controller <NUM> may use the quantity of the light as it is to make a decision based on a threshold value. Alternatively, the smoke detector <NUM> may convert the quantity of light received at the photosensitive element <NUM> into a smoke concentration and then transmit a detection signal, having a voltage level representing the smoke concentration, to the controller <NUM>.

The smoke detector <NUM> may further include an amplifier circuit for amplifying the electrical signal provided by the photosensitive element <NUM>, a converter circuit for performing an analog-to-digital conversion on the electrical signal, and other circuits. Alternatively, the amplification and analog-to-digital conversion of the electrical signal provided by the photosensitive element <NUM> may be performed by the circuit modules. Also, the number of the optical element <NUM> for use to detect smoke does not have to be one but may also be plural.

The indicator <NUM> is an indicator lamp notifying an external device of the operating status of the sensor <NUM>. In a normal mode (i.e., in a fire monitoring mode), a lighting circuit of the circuit module turns the light source OFF under the control of the controller <NUM>. On the other hand, when a decision is made that a fire should be present, the lighting circuit of the circuit module starts flickering or lighting the light source under the control of the controller <NUM>. In <FIG>, illustration of the lighting circuit between the controller <NUM> and the indicator <NUM> is omitted.

The controller <NUM> may be implemented as a computer system including one or more processors (microprocessors) and one or more memories. In other words, the functions of the controller <NUM> are performed by making the one or more processors execute a program (application) stored in the one or more memories. In this embodiment, the program is stored in advance in the memory of the controller <NUM>. Alternatively, the program may also be downloaded via a telecommunications line such as the Internet or distributed after having been stored in a nontransitory storage medium such as a memory card.

The controller <NUM> is configured to control the communications interface <NUM> and circuit modules (including the lighting circuit and the power supply circuit).

In addition, the controller <NUM> is also configured to receive detection signals from the heat detector <NUM> and the smoke detector <NUM> to determine whether or not a fire is actually present. Specifically, the controller <NUM> monitors the respective detection signals provided by the six heat detecting elements <NUM> of the heat detector <NUM> on an individual basis, and decides, on finding at least one heat detecting element <NUM>, of which the signal level (corresponding to a resistance value) included in the detection signal is greater than (or less than) the threshold value, that a fire should be present. In addition, the controller <NUM> also monitors the detection signal provided by the smoke detector <NUM> and decides, on finding the signal level included in the detection signal greater than (or less than) a threshold value (indicating that the smoke has reached the smoke detector <NUM>), that a fire should be present.

On deciding, based on either the signal level of the heat detection or the signal level of the smoke detection, that a fire should be present, the controller <NUM> makes the communications interface <NUM> transmit a signal alerting a person to the presence of the fire to a receiver, fire alarm devices, and other devices of an automatic fire alarm system. The communications interface <NUM> may be implemented as a communications interface for communicating, via cables, for example, with the receiver, the fire alarm devices, and other devices. The communications interface <NUM> is connected to communicate with the receiver, the fire alarm devices, and other devices via the connection pieces of the mounting member, the connector portion of the attachment base, and the signal cables provided on the backside of the ceiling. In addition, on deciding that a fire should be present, the controller <NUM> outputs a control signal for flickering or lighting the light source of the indicator (indicator lamp) to the lighting circuit of the circuit module.

The flow channel forming member <NUM> according to the first embodiment is made of a synthetic resin and may be made of flame-retardant ABS resin, for example. The flow channel forming member <NUM> has a compressed, generally circular cylindrical shell, of which the upper surface is opened. Specifically, the flow channel forming member <NUM> includes a ringlike body <NUM> and a single or a plurality of (e.g., four in this example) terminal stages <NUM> as shown in <FIG>. The body <NUM> has an inner wall <NUM> and an outer wall <NUM> surrounding the inner wall <NUM>. The outer wall <NUM> is provided with a plurality of (e.g., four in this example) outwardly extended portions <NUM>. Each of the extended portions <NUM> has, at the tip thereof, a downwardly protruding hook <NUM>. The outer wall <NUM> has a sloped surface <NUM> as its outer peripheral surface. The sloped surface <NUM> is sloped up toward the center of the outer wall <NUM> as the distance to the top of the outer wall <NUM> decreases. In this example, part of each extended portion <NUM> is configured to serve as the terminal stage <NUM>. The flow channel forming member <NUM> has a hole <NUM> penetrating through a central area thereof in the upward/downward direction. Having each hook <NUM> hooked on an associated protruding piece <NUM> of the board <NUM> allows the flow channel forming member <NUM> to be fixed onto the board <NUM>. In addition, the outer wall <NUM> also has the plurality of insert holes <NUM> mentioned above, into which the connection pieces <NUM> of the upper cover <NUM> are inserted.

Each terminal stage <NUM> is a structural element having a terminal to be electrically connected to the board <NUM> and used to secure the board <NUM> with a screw. The terminals are electrically connected to the conductor pattern on the board <NUM>. The sensor <NUM> is powered by a commercial power supply from over the installation surface <NUM> (e.g., the ceiling surface in the first embodiment) and receives or transmits various types of communication signals via the terminals, the connection pieces <NUM>, the attachment base, and other members.

The smoke detector <NUM> is installed on the board <NUM>. The inner wall <NUM> is arranged to surround the smoke detector <NUM> with a gap left with respect to the smoke detector <NUM>.

The sloped surface <NUM> is sloped up, when the smoke detector <NUM> is viewed in one direction through one of the openings <NUM>, such that its height increases in the vertical direction A1 as the distance to the smoke detector <NUM> decreases in that direction. The sloped surface <NUM> forms the outer peripheral surface of the outer wall <NUM> and the height of the sloped surface <NUM> corresponds to the height of the outer wall <NUM>. Thus, the flow channel <NUM> is formed so as to cause the gas (hot air) that has flowed into the internal space SP1 of the housing <NUM> through one of the openings <NUM> to flow along the sloped surface <NUM> and go up toward the top of the smoke detector <NUM>. Specifically, the internal space SP1 is surrounded with the upper cover <NUM>, the flow channel forming member <NUM>, and the smoke detector <NUM>.

Each heat collector <NUM> is configured to collect the hot air toward its associated heat detecting element <NUM>. The same number of (e.g., six in the first embodiment) heat collectors <NUM> as that of the heat detecting elements <NUM> are installed. In other words, the sensor <NUM> includes six heat collectors <NUM>. The respective heat collectors <NUM> are arranged on, and formed integrally with, the bottom member <NUM> of the lower cover <NUM>. Specifically, the six heat collectors <NUM> are provided outside of the cylindrical portion <NUM> (see <FIG>). Each of the heat collectors <NUM> may be made of, for example, flame-retardant ABS resin.

In the first embodiment, each heat collector <NUM> is provided under its associated heat detecting element <NUM>. As shown in <FIG>, the heat detecting elements <NUM> and the heat collectors <NUM> are arranged to overlap with each other when viewed along the thickness of the board <NUM>. Each heat collector <NUM> is formed to protrude upward in the vertical direction A1 from the bottom member <NUM>. The respective heat collectors <NUM> are provided between the board <NUM> and the bottom member <NUM> that faces the board <NUM>. <FIG> is a cross-sectional view taken along a plane that passes through not only the center of the sensor <NUM> shown in <FIG> as viewed from under the sensor <NUM> but also two heat detecting elements <NUM> that face each other diagonally. <FIG> is a front view of a principal portion of the sensor <NUM> shown in <FIG> as viewed in the direction indicated by the arrow Y in <FIG>. In <FIG>, the heat detecting elements <NUM> is provided to horizontally face a beam <NUM> that prevents a human from putting his or her on the heat detecting element <NUM>. Specifically, the heat detecting element <NUM> is provided to horizontally face the beam <NUM> that is located between two adjacent openings <NUM> out of the plurality of openings <NUM>. Furthermore, the heat collector <NUM> is provided under the heat detecting element <NUM>.

Each heat collector <NUM> has a circumferentially sloped surface <NUM> sloped up, along the circumference A3 of the housing <NUM>, toward the heat detecting element <NUM> so as to increase its height in the vertical direction A1 as the distance to the heat detecting element <NUM> decreases as shown in <FIG>, <FIG>, <FIG>, and <FIG>. In addition, the heat collectors <NUM> and the heat detecting elements <NUM> overlap with each other along the thickness of the board <NUM>. Thus, in the first embodiment, the heat collectors <NUM> provided are as many as the heat detecting elements <NUM> provided. In the first embodiment, when projected onto the board <NUM> in the vertical direction A1 (i.e., when viewed along the thickness of the board <NUM>), each heat collector <NUM> has a substantially trapezoidal shape as shown in <FIG>. Also, in the first embodiment, each heat collector <NUM> has a substantially triangular shape when its associated openings <NUM> are viewed straight from the external space SP2 as shown in <FIG> and the <NUM>. This makes it easier, when hot air has come from both sides of each heat collector <NUM> along the circumference A3 to the heat collector <NUM>, for example, for the hot air to go up the two circumferentially sloped surfaces <NUM> of the heat collector <NUM> and eventually reach the heat detecting element <NUM>. Thus, providing the heat collector <NUM> enables collecting heat toward the heat detecting element <NUM> more easily than in a situation where no heat collectors <NUM> are provided. This enables collecting heat at the outbreak of fire, thus contributing to improving the thermal response. In addition, even when a heating test is conducted using the heating tester <NUM>, for example, enabling collecting heat in this manner contributes to improving the thermal response as well.

Next, it will be described how the sensor <NUM> according to the first embodiment performs the operation of detecting hot air while a heating test is conducted using the heating tester <NUM>.

<FIG> illustrates how the heating tester <NUM> is attached to cover the sensor <NUM>. The heating tester <NUM> is attached to the sensor <NUM> such that the heat source H10 of the heating tester <NUM> falls just between two adjacent heat detecting elements <NUM>. In this example, the heat source H10 and each of the two adjacent heat detecting elements <NUM> are supposed to be shifted from each other by approximately <NUM> degrees. This example will be described on the supposition that the heat source H10 and the heat detecting elements <NUM> are arranged at worst positions, i.e., at such positions where the heat is detectible least smoothly. However, this is only an example and the heat source H10 and the heat detecting elements <NUM> may naturally be arranged at other positions.

If the heat source H10 and each of the two adjacent heat detecting elements <NUM> are shifted from each other by approximately <NUM> degrees, then the hot air H30 coming from the heat source H10 collides against the beam <NUM>, the board <NUM>, and other members and thereby separated into hot air H30L flowing to the left as viewed from the beam <NUM> and hot air H30R flowing to the right as viewed from the beam <NUM>.

When reaching another beam <NUM>, each of the hot air H30R, H30L flows toward the nearest heat detecting element <NUM>. When reaching the region surrounding the tongue portion <NUM>, each of the hot air H30R, H30L collides against the heat collector <NUM> and goes up the circumferentially sloped surface <NUM> of the heat collector <NUM>. Without the heat collector <NUM>, the hot air would pass over or under the board <NUM>. In that case, the heat of the hot air would not be collected easily, and it would take a long time to collect the heat. On the other hand, the sensor <NUM> according to the first embodiment may catch the hot air and collect its heat due to the presence of the heat collectors <NUM>. <FIG> illustrates the distribution of the hot air. <FIG> is a cross-sectional view taken along the plane X-X shown in <FIG> and passing through one of the heat detecting elements <NUM> shown in <FIG>. The heat detecting element <NUM> is provided at the tip of the tongue portion <NUM> and the hot air H20 is collected by the heat collector <NUM> to wrap the tongue portion <NUM> having the heat detecting element <NUM>, thereby causing an increase in the heat collecting rate. Thus, a sensor <NUM> contributing to improving the thermal response may be provided. In addition, the sensor <NUM> may also contribute to improving the thermal response even when a heating test is conducted using the heating tester <NUM> with a localized heat source H10.

As can be seen from the foregoing description, a sensor <NUM> according to the first embodiment includes: a board <NUM>; a heat detecting element <NUM> mounted on the board <NUM> to detect heat; a housing <NUM> that houses the board <NUM>; and a heat collector <NUM>. The housing <NUM> has a flow channel <NUM> and an opening <NUM>. The flow channel <NUM> is provided in an internal space SP1 of the housing <NUM> and allows hot air to flow therethrough. The opening <NUM> allows the flow channel <NUM> to communicate with an external space SP2 outside of the housing <NUM>. The heat detecting element <NUM> is disposed to fall inside the opening <NUM> when the opening <NUM> is viewed straight from the external space SP2. The heat collector <NUM> is configured to collect the hot air toward the heat detecting element <NUM>.

According to this configuration, the sensor <NUM> achieves the advantage of contributing to improving the thermal response. In particular, the improvement of the thermal response allows even the heating tester <NUM>, of which the heat source H10 is a localized one, to achieve the advantage of having the heating test done in a shorter time.

Note that the embodiment described above is only an exemplary one of various embodiments of the present disclosure and should not be construed as limiting. Rather, the exemplary embodiment may be readily modified in various manners depending on a design choice or any other factor without departing from the scope of the present disclosure.

Next, variations of the exemplary embodiment described above will be enumerated one after another. Note that the variations to be described below may be adopted in combination as appropriate. Also, in the following description, the embodiment described above will be hereinafter sometimes referred to as a "basic example.

In the basic example described above, the sensor <NUM> includes the gas flow control walls <NUM>. However, the gas flow control walls <NUM> are not essential constituent elements for the sensor <NUM> according to the present disclosure but may be omitted as appropriate.

In the basic example described above, the number of the gas flow control walls <NUM> provided is three. However, this is only an example and should not be construed as limiting. Alternatively, the number of the gas flow control walls <NUM> provided may also be two or even four or more.

In the basic example described above, the board <NUM> on which the smoke detector <NUM> is mounted is a circuit board on which the controller <NUM> and other circuit components are also mounted. However, this is only an example and should not be construed as limiting. Alternatively, the board <NUM> may also be provided separately from the circuit board on which the controller <NUM> and other circuit components are mounted. Nevertheless, the basic example contributes more effectively to cutting down the number of members required.

In the basic example described above, the heat collectors <NUM> each have a triangular shape in front view. However, this is only an example and should not be construed as limiting. Alternatively, the heat collectors 16A may also each have a trapezoidal shape in front view as shown in <FIG>. The heat collector 16A having such a trapezoidal shape has two circumferentially sloped surfaces 19A and a trapezoidal upper surface 19B as a plane surface. The heat collector 16A with such a shape also allows the hot air coming from around the heat collector 16A to go up the circumferentially sloped surfaces 19A and reach its associated heat detecting element <NUM>. Thus, the heat collector 16A contributes to improving the thermal response as effectively as the heat collector <NUM> with the triangular shape.

Each of the heat collectors <NUM> of the basic example may also be modified to have a radially sloped surface. As shown in <FIG>, such a heat collector 16C may have a radially sloped surface <NUM> sloped up, along the radius A2 of the housing <NUM>, toward the heat detecting element <NUM> so as to increase its height in the vertical direction A1 as the distance to the heat detecting element <NUM> decreases. In this case, the radius A2 is supposed to be directed from the center of the sensor <NUM> as viewed from under the sensor <NUM> toward the outer peripheral edge thereof. Providing such a radially sloped surface <NUM> makes it even easier for the hot air to go up the heat collector 16C. Thus, the heat collector 16C contributes to improving the thermal response as effectively as the heat collector <NUM> with the triangular shape.

In the basic example described above, each heat collector <NUM> is configured in a triangular shape in front view. However, this configuration is only an example and should not be construed as limiting. Alternatively, the heat collector <NUM> having the triangular shape in front view may be extended horizontally along the radius A2 of the sensor <NUM> through the outer peripheral edge <NUM> of the bottom member <NUM> of the lower cover <NUM> as shown in <FIG>. In that case, the heat collector 16D is provided between the board <NUM> and the bottom member <NUM> that forms the bottom of the opening <NUM> and facing the board <NUM>. When viewed along the thickness of the board <NUM>, the outer peripheral edge <NUM> of the bottom member <NUM> and the outer edge of the heat collector 16D are aligned with each other. The heat collector 16D not only produces the heat collecting effect but also serves as a finger guard for preventing a human from putting his or her finger on the heat detecting element <NUM> through the opening <NUM>. This allows a member that plays the role of the finger guard in a known structure to be omitted.

The sensor <NUM> of the basic example may be modified to further include guide portions 17A, each of which guides the hot air flowing in through one of the openings <NUM> toward its associated heat detecting element <NUM>. As shown in <FIG>, each guide portion 17A is formed on an associated terminal stage <NUM> (see <FIG>) and is sloped from one of the openings <NUM> toward its associated heat detecting element <NUM>. Specifically, each guide portion 17A is provided on an associated extended portion <NUM> (see <FIG>), a part of which serves as the terminal stage <NUM>. As in the first embodiment, each heat detecting element <NUM> is mounted on the lower surface of an associated tongue portion <NUM> and provided around a tip of the tongue portion <NUM>. Each guide portion 17A is configured as a terminal stage 22A serving as not only a beam <NUM> but also a terminal stage <NUM> as well. As shown in <FIG>, the terminal stage 22A serving as not only a beam <NUM> but also a terminal stage <NUM> has a sloped surface connecting the beam <NUM> to the terminal stage <NUM> in top view. In front view, the sloped surface is sloped toward the heat detecting element <NUM>. Thus, the terminal stage 22A (guide portion 17A) guides the hot air toward the heat detecting element <NUM>. The terminal stage 22A is arranged not to overlap with any tongue portion <NUM> of the board <NUM>. Thus, making the terminal stage 22A also serve as the guide portion 17A allows cutting down the material to use.

As shown in <FIG>, the sensor <NUM> of the basic example may be modified to further include guide portions 17B, each of which guides the hot air flowing in through one of the openings <NUM> toward its associated heat detecting element <NUM>. As in the first embodiment, each heat detecting element <NUM> is mounted on the lower surface of an associated tongue portion <NUM> and provided around a tip of the tongue portion <NUM>. For example, the guide portions 17B are formed on the beams <NUM> (25A, 25B) as shown in <FIG>. A beam 25A (guide portion 17B), arranged to face one of the heat detecting elements <NUM> of the board <NUM>, may have the shape of an equilateral triangle, for example, one vertex of which is provided to face the heat detecting element <NUM>. On the other hand, another beam 25B (guide portion 17B), arranged not to face any heat detecting element <NUM>, is provided between two adjacent heat detecting elements <NUM> and has a trapezoidal shape. The beam 25B with the trapezoidal cross section is provided to be convex toward the external space SP2. Using these two types of beams 25A, 25B in combination makes it even easier for the hot air flowing in through any of the openings <NUM> to be separated to the right and to the left by the beams 25B and to be directed toward the heat detecting element <NUM> by the beams 25A. This contributes to improving the thermal response of the sensor <NUM>. In this variation, the beams 25A, 25B are supposed to be used in combination. Alternatively, either the beams 25A or the beams 25B may be used selectively.

As shown in <FIG>, the sensor <NUM> of the basic example may be modified to further include guide portions 17C, each of which guides the hot air flowing in through one of the openings <NUM> toward its associated heat detecting element <NUM>. As in the first embodiment, each heat detecting element <NUM> is mounted on the lower surface of an associated tongue portion <NUM> and provided around a tip of the tongue portion <NUM>. As shown in <FIG>, the sensor <NUM> includes guide portions 17C. Each of the guide portions 17C has the shape of blades <NUM>. Each guide portion 17C is provided for an associated beam <NUM> and has the blades <NUM>, each of which is sloped from one of the openings <NUM> toward an associated heat detecting element <NUM>. The guide portions 17C and the beams <NUM> are formed integrally with the bottom member 18A of the lower cover <NUM> (see <FIG>). In other words, the blades <NUM> of the guide portions 17C and the beams <NUM> form integral parts of the bottom member 18A. Each of the multiple pairs (e.g., six pairs in the example illustrated in <FIG>) of blades <NUM> (guide portions 17C) is spaced from adjacent pairs of blades <NUM>. These pairs of blades <NUM> are arranged such that a virtual line connecting together two adjacent blades <NUM> passes by the heat detecting element <NUM> located between the two adjacent blades <NUM>. In that case, the hot air coming from the heat source H10 of the heating tester <NUM>, for example, will be guided to the heat detecting element <NUM>. Therefore, these guide portions 17C are configured to more smoothly guide the hot air toward the heat detecting elements <NUM>, thus contributing to improving the thermal response.

As shown in <FIG>, the sensor <NUM> of the basic example may be modified to further include guide portions 17D, each of which guides the hot air flowing in through one of the openings <NUM> toward its associated heat detecting element <NUM>. As in the first embodiment, each heat detecting element <NUM> is mounted on the lower surface of an associated tongue portion <NUM> and provided around a tip of the tongue portion <NUM>. The sensor <NUM> according to this tenth variation includes the upper member <NUM> (see <FIG>) and a plurality of (e.g., six in the example illustrated in <FIG>) beams <NUM>. Each of the guide portions 17D is provided between a pair of beams <NUM>. The bottom member 18B is provided with wall surfaces <NUM> (guide portions 17D), each of which couples together two adjacent beams <NUM> out of the plurality of beams <NUM> and has either a curved shape or a linear shape. In this variation, the wall surfaces <NUM> are formed on the bottom member 18B. Each wall surface <NUM> that couples together two adjacent beams <NUM> and that has either a curved shape or a linear shape is formed to pass by an associated heat detecting element <NUM>. In that case, the hot air coming from the heat source H10 of the heating tester <NUM>, for example, will be guided along the wall surface <NUM> to the heat detecting element <NUM>. Therefore, these guide portions 17D are configured to more smoothly guide the hot air toward the heat detecting elements <NUM>, thus contributing to improving the thermal response.

In the basic example described above, the heat detecting elements <NUM> and the heat collectors <NUM> are arranged to overlap with each other when viewed along the thickness of the board <NUM>. However, this configuration is only an example and should not be construed as limiting. Alternatively, the heat detecting elements <NUM> and triangular heat collectors <NUM> may also be arranged such that no vertices of each heat collector <NUM> overlap with any heat detecting element <NUM> (i.e., the vertices of each heat collector <NUM> shift from the heat detecting elements <NUM>) when viewed along the thickness of the board <NUM>. In addition, a gap is left between each heat detecting element <NUM> and its associated heat collector <NUM> as shown in <FIG>. To enable the hot air to pass smoothly, each heat detecting element <NUM> and its associated heat collector <NUM> preferably have a gap left between themselves. For example, even if any vertex of a heat collector <NUM> is located above its associated heat detecting element <NUM> in the vertical direction A1 but if the vertex of the heat collector <NUM> and the heat detecting element <NUM> are shifted from each other, then a gap may still be left between the heat collector <NUM> and the heat detecting element <NUM>.

In a second embodiment, the heat detecting elements <NUM> are implemented as lead thermistors <NUM> (heat detecting elements <NUM>) instead of chip thermistors, which is a major difference from the first embodiment. The following description of the second embodiment with reference to <FIG> will be focused on the differences from the first embodiment. In the following description, any constituent element of this second embodiment, having the same function as a counterpart of the first embodiment described above, will be designated by the same reference numeral as that counterpart's, and description thereof will be omitted as appropriate herein. The drawings to be referred to in the following description of the second embodiment are all schematic representations. That is to say, the ratio of the dimensions (including thicknesses) of respective constituent elements illustrated on the drawings does not always reflect their actual dimensional ratio.

A sensor 1A according to the second embodiment includes: a board 10A; a heat detecting element <NUM> mounted on the board 10A to detect heat; a housing <NUM> that houses the board 10A; and a heat collector <NUM>. The housing <NUM> has a flow channel <NUM> provided in an internal space SP1 of the housing <NUM> and allowing air to flow therethrough and an opening <NUM> allowing the flow channel <NUM> to communicate with an external space SP2 outside of the housing <NUM>. The heat detecting element <NUM> is disposed to fall inside an opening area <NUM> of the opening <NUM> when the opening area <NUM> of the opening <NUM> is viewed straight from the external space SP2. The heat collector <NUM> is configured to collect hot air toward the heat detecting element <NUM>.

The heat detecting elements <NUM> for use in the second embodiment are lead thermistors <NUM>. In the second embodiment, the lead thermistors <NUM> are negative thermal coefficient thermistors. That is to say, the lead thermistors <NUM> are heat detecting elements <NUM>, of which the resistance value decreases as the temperature increases.

The lead thermistors <NUM> are connected to the board 10A as shown in <FIG>. The lead thermistors <NUM> are provided to protrude downward in the vertical direction A1 from the lower surface of the board 10A. On the lower surface of the board 10A, a single or a plurality of (e.g., four in the second embodiment) lead thermistors <NUM> are provided. The lead thermistors <NUM> are arranged at regular intervals (i.e., approximately every <NUM> degrees). The board 10A is not provided with any tongue portions <NUM> described for the first embodiment but has a substantially disklike shape.

The heat collectors <NUM> are provided between the lead thermistors <NUM> and the bottom member <NUM> of the lower cover <NUM>. A gap is left between the heat collectors <NUM> and the lead thermistors <NUM>. In this embodiment, the heat collectors <NUM> may have, for example, a triangular shape as shown in <FIG>.

Next, it will be described how the sensor 1A according to the second embodiment performs the operation of detecting hot air while a heating test is conducted using the heating tester <NUM>.

The heating tester <NUM> is attached to the sensor 1A and hot air coming from the heat source H10 of the heating tester <NUM> is allowed to flow into the internal space SP1 of the sensor 1A through one of the openings <NUM> of the sensor 1A. When flowing into the internal space SP1 of the sensor 1A through one of the openings <NUM>, the hot air is obstructed by the rectangular parallelepiped beams <NUM>, which connect the bottom member <NUM> of the lower cover <NUM> to the upper member <NUM> thereof, and the board 10A, for example. Thus, the hot air that has collided against the beams <NUM>, the board 10A, and other members is separated to the right and to the left. Then, the hot air separated to the right and to the left enters the internal space SP1 of the sensor 1A to reach the heat collectors <NUM> provided on the bottom member <NUM>. The hot air that has reached the heat collector <NUM> goes up the circumferentially sloped surfaces <NUM> of the heat collectors <NUM>. Then, the hot air reaches the lead thermistors <NUM> which are provided over the heat collectors <NUM> with a gap left between themselves in the vertical direction A1. Without the heat collectors <NUM>, the hot air would pass through the gap between the board 10A and the bottom member <NUM> and leave the internal space SP1 through an outlet port H40 of the heating tester <NUM>. In contrast, providing the heat collectors <NUM> makes it easier to collect the hot air around the lead thermistors <NUM>. Consequently, the sensor 1A contributes to improving the thermal response.

Next, variations will be enumerated one after another. Note that the variations to be described below may be adopted as appropriate in combination with the second embodiment described above.

In the second embodiment described above, the lead thermistors <NUM> are supposed to be negative thermal coefficient thermistors. However, this configuration is only an example and should not be construed as limiting. Alternatively, positive thermal coefficient thermistors may also be used.

In the second embodiment described above, the sensor 1A includes rectangular parallelepiped beams <NUM>. However, this configuration is only an example and should not be construed as limiting. Alternatively, the beams <NUM> may also include guide portions 17B (see <FIG>) with beams 25A formed in a triangular pyramid shape or beams 25B formed in a truncated pyramid shape. Providing the guide portions 17B makes it easier for the hot air to flow toward the heat collectors <NUM>, thus contributing to improving the thermal response.

In the second embodiment described above, the sensor 1A includes rectangular parallelepiped beams <NUM>. However, this configuration is only an example and should not be construed as limiting. Alternatively, the sensor 1A may also include terminal stages 22A as the guide portions 17A and the beams <NUM> may also be used as the terminal stages <NUM> (see <FIG>). This also makes it easier for the hot air to flow toward the heat collectors <NUM>, thus contributing to improving the thermal response.

Claim 1:
A sensor (<NUM>, 1A) comprising:
a board (<NUM>, 10A);
a heat detecting element (<NUM>) mounted on the board (<NUM>, 10A) and configured to detect heat;
a housing (<NUM>) that houses the board (<NUM>, 10A);
a heat collector (<NUM>, 16A, 16C, 16D); and
a bottom member (<NUM>, 18A, 18B) forming a bottom of an opening (<NUM>) of the housing (<NUM>) and facing the board (<NUM>, 10A),
the bottom member (<NUM>, 18A. 18B) being formed integrally with the heat collector (<NUM>, 16A, 16C, 16D),
the housing (<NUM>) having: a flow channel (<NUM>) provided in an internal space (SP1) of the housing (<NUM>) and allowing air to flow therethrough; and the opening (<NUM>) allowing the flow channel (<NUM>) to communicate with an external space (SP2) outside of the housing (<NUM>),
the heat collector (<NUM>, 16A, 16C, 16D) being configured to collect hot air toward the heat detecting element (<NUM>),
the heat detecting element (<NUM>) and the heat collector (<NUM>, 16A, 16C, 16D) being arranged to overlap with each other when viewed along a thickness of the board (<NUM>, 10A); and
the heat collector (<NUM>, 16A, 16C, 16D) being provided between the board (<NUM>, 10A) and the bottom member (<NUM>, 18A, 18B) and having a circumferentially sloped surface (<NUM>) sloped up, along a circumference of the housing (<NUM>), toward the heat detecting element (<NUM>) so as to increase its height in a vertical direction (A1) as a distance to the heat detecting element (<NUM>) decreases in a state wherein the sensor (<NUM>, 1A) is installed on a ceiling surface.