JP2013008084A - Fire sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire sensor capable of preventing water from accumulating within a main body.SOLUTION: The fire sensor includes: a detection section 3 that detects a fire; a body 5 that stores the detection section 3; and a main body 2 having a plate cover 8 attached to the body 5. The body 5 has a drain groove 22 formed enclosing the cover 8 for draining water accumulated on an upper face of the cover 8. The drain groove 22 has a drain hole 22a formed at the bottom thereof for draining water flowing into the drain groove 22. The drain groove 22 has a lead-in section 26 formed in the entire periphery thereof for leading water flowing in the drain groove 22 into the drain hole 22a by means of capillary phenomenon.

Description

  The present invention relates to a fire detector.

  Conventionally, there has been proposed a fire detector that detects heat generated by a fire using a heat sensing means (for example, Patent Document 1).

  In Patent Document 1, as shown in FIG. 11, a circuit board on which a base 71 attached to a ceiling 81, a body 72 detachably attached to the base 71, and a circuit component 85 constituting a sensing circuit are mounted. 73 is disclosed. The fire detector includes a thermistor 74 as a sensing means, a protector 75 attached to the lower surface of the body 72 to protect the thermistor 74, and a confirmation lamp 76 attached to the body 72 so as to extend from the lower surface of the body 72. And have.

  The body 72 is formed in a bottomed cylindrical shape that opens upwardly toward the top. Inside the body 72, a pair of electric wire connection portions 80 to which signal lines (not shown) drawn from signal line drawing holes 81a formed in the ceiling 81 are connected are arranged (see FIG. 12). Here, the base 71 is formed in a disc shape, and a cross-shaped lead-out hole 82 is formed in the center thereof.

  A recessed portion 83 having a trapezoidal cross section is formed in the center of the lower surface of the body 72. A central hole 72 a is formed in the center of the recess 83. The thermistor 74 extends from the center hole 72a of the body 72 to the lower surface.

  An annular wall 72c projects from the inner bottom surface of the body 72 so as to surround the central hole 72a. Further, an insertion hole 76 a for inserting the confirmation lamp 76 is formed in the bottom wall of the body 72.

  Also, the inner bottom surface of the body 72 includes a center hole 72a and an insertion hole 76a in plan view so that the center portion of the body 72 is displaced from the center of the body 72 so as to avoid the wire connection portion 80 while enclosing the annular wall 72c. A peripheral wall 72d is provided so as to be substantially symmetrical with respect to the center line passing through the center line 72d. A drain hole 77 is formed in the bottom wall of the body 72.

  The circuit board 73 is stored in a storage space 84 formed by the peripheral wall 72 d of the body 72. The circuit board 73 is protected by a back cover 79 fastened and fixed to the body 72 by a fixing screw 78 (see FIG. 12). The back cover 79 has an upper surface inclined at an angle θ with respect to the horizontal.

JP 2001-216578 A

  By the way, in the fire detector having the configuration shown in FIG. 11, since the upper surface of the back cover 79 is inclined by an angle θ with respect to the horizontal, even if water is generated on the upper surface of the back cover 79 due to condensation or the like, Water flows down from the back cover 79 to the inner bottom surface of the body 72 by gravity, and drainage is possible from the drain hole 77.

  However, in the fire detector having the configuration shown in FIG. 11, even if water generated on the upper surface of the back cover 79 flows down from the back cover 79 to the inner bottom surface of the body 72 due to gravity, the fire detector is far from the drain hole 77. When it flows down, there is a concern that this water stays on the outer peripheral surface side of the peripheral wall 72d on the inner bottom surface of the body 72 (main body portion) and does not flow to the drain hole 77.

  This invention is made | formed in view of the said reason, The objective is to provide the fire detector which can suppress that water retains in a main-body part.

  A fire detector according to the present invention is a fire detector including a main body having a detector that detects the occurrence of a fire, a body that houses the detector, and a plate-like cover that is attached to the body. The body is provided with a drainage groove for draining water adhering to the upper surface of the cover so as to surround the cover, and drains the water flowing into the drainage groove at the bottom of the drainage groove. A drainage hole is provided, and a pull-in portion is provided over the entire circumference of the drainage groove to draw water flowing into the drainage groove into the drainage hole by a capillary phenomenon.

  In the fire detector of the present invention, it is possible to suppress water from staying in the main body.

The main-body part in the fire sensor of embodiment is shown, (a) is the perspective view which fractured | ruptured partially, (b) is the schematic sectional drawing which was fractured | ruptured partially. It is the disassembled perspective view seen from the upper side in the main-body part of a fire detector same as the above. It is the disassembled perspective view seen from the lower side in the main-body part of a fire detector same as the above. The main part of a fire detector same as the above is shown, (a) is a perspective view seen from the upper side, (b) is a perspective view seen from the lower side. It is a top view which shows the main exterior of a fire detector same as the above. The main part of a fire detector same as the above is shown, (a) is an upper side view, (b) is a left side view, (c) is a front view, (d) is a right side view, and (e) is a lower side view. is there. Regarding the main body of the above-described fire detector, (a) is a plan view showing a state in which a circuit board provided with a light emitting element and a light guide are housed in the body, and (b) is an enlarged perspective view of a main part of the body. It is explanatory drawing which shows the location where water stagnated in the drain ditch in the case where a drawing-in part is not provided in the fire detector same as the above. The base of the fire detector same as the above is shown, (a) is a perspective view seen from the upper side, (b) is a perspective view seen from the lower side. The fire detector same as the above is shown, (a) is a perspective view seen from the upper side, (b) is a perspective view seen from the lower side. It is sectional drawing of the fire detector of a prior art example. It is a top view of the detector main body in the fire detector same as the above.

  Hereinafter, the fire detector of the present embodiment will be described with reference to FIGS.

  The fire detector of the present embodiment is a fire detector attached to a construction surface such as a ceiling surface, for example, and includes a base 1 (see FIGS. 9 and 10) attached to a construction surface (not shown), a base 1 is provided with a detachable main body 2. This fire detector has a smoke sensing function for sensing smoke and a heat sensing function for sensing heat.

  The base 1 is formed in a shallow bottomed cylindrical shape whose lower surface side is opened by, for example, synthetic resin. At the center of the bottom wall 1a of the base 1, there is an insertion hole 1c through which a power line (not shown) derived from an opening hole (not shown) on the construction surface and a feed wiring (not shown) can be inserted. It is penetrating. Hereinafter, for convenience of explanation, the power supply line and the feed wiring are collectively referred to as an electric wire.

  In addition, two electric wire connection portions 13 that can be electrically connected to the electric wires are arranged on the main body 2 side of the bottom wall 1a of the base 1 (on the lower surface side in FIG. 9B). In the fire detector of the present embodiment, one electric wire connecting portion 13 is a first electric wire connecting portion 13a for supplying power, and the other electric wire connecting portion 13 is a second electric wire connecting portion 13b for feed wiring. In the present embodiment, the first electric wire connecting portion 13a and the second electric wire connecting portion 13b are provided. However, the present invention is not limited thereto, and for example, only the first electric wire connecting portion 13a may be provided. .

  Each electric wire connection portion 13 is provided with a pair of insertion holes 14 and 14 into which a pair of core wires (not shown) of the electric wire can be inserted. In the fire detector of the present embodiment, one pair of insertion holes 14 and 14 is a pair of first insertion holes 14a and 14a for power supply, and the other pair of insertion holes 14 and 14 is a pair of second grounding holes. The insertion holes 14b and 14b are used.

  In addition, each electric wire connecting portion 13 is provided between a terminal plate (not shown) that can be electrically connected to the pair of core wires of the electric wire inserted into the pair of insertion holes 14 and 14 and the terminal plate. Two quick-connecting terminals (not shown) comprising lock springs (not shown) that sandwich the pair of core wires of the electric wire are housed.

  Further, four connection terminal portions 17 that can be electrically connected to the main body 2 are arranged on the main body 2 side of the bottom wall 1a of the base 1. In the fire detector according to the present embodiment, two of the four connection terminal portions 17 are the first connection terminal portions 17a for supplying power, and the remaining two connection terminal portions 17 are the second connection wiring portions 17. The connection terminal portion 17b is used. In the present embodiment, the first connection terminal portion 17a and the second connection terminal portion 17b are provided. However, the present invention is not limited to this. For example, only the first connection terminal portion 17a may be provided. .

  By the way, on the main body 2 side of the bottom wall 1a of the base 1, the first connection pieces 15a extending from the respective terminal plates of the respective quick connection terminals of the first electric wire connecting portion 13a are arranged. The tip of the first connection piece 15a is electrically connected to each first connection terminal portion 17a separately. Moreover, the 2nd connection piece 15b extended from each terminal plate of each quick connection terminal of the 2nd electric wire connection part 13b is arrange | positioned at the main-body part 2 side of the bottom wall 1a of the base 1, These The tip of the second connection piece 15b is electrically connected to each second connection terminal portion 17b separately.

  In addition, a pair of arc-shaped attachment holes 1d and 1d for attaching the base 1 to the construction surface are penetrated through the bottom wall 1a of the base 1. Each attachment hole 1d is provided with an attachment screw insertion hole 1j through which an attachment screw (not shown) for attaching the base 1 to the construction surface is inserted from the lower surface side of the base 1. In the fire detector according to the present embodiment, first, each mounting screw is individually inserted from the lower surface side of the base 1 into each mounting screw insertion hole 1j, and each mounting screw is provided on the base 1 side of the construction surface. Temporarily fix in a screw hole (not shown). In this state, the base 1 is rotated in the circumferential direction of the bottom wall 1a of the base 1 so that each mounting screw moves to the position of each mounting hole 1d. The base 1 is attached to the construction surface by being screwed together.

  The main body 2 includes a detection unit 3 that detects the occurrence of a fire, a light emitting element 6 that includes a first light emitting diode, and a light guide that emits light from the light emitting element 6 through the incident surface 7a and exits from the output surface 7b. It has a body 7, a body 5 that houses the detector 3, the light emitting element 6, and the light guide 7, and a plate-like (for example, disc-like) cover 8 that is attached to the body 5. In addition, in this embodiment, although the light emitting element 6 and the light guide 7 are provided 2 each, these numbers are not specifically limited, For example, one may be sufficient.

  The detection unit 3 includes a circuit board 4 on which a detection circuit (not shown) for detecting the occurrence of a fire is formed, a smoke detection circuit (not shown) formed on the circuit board 4 for detecting smoke, and a second A light projecting element (not shown) made of a light emitting diode, a light receiving element (not shown) made of a photodiode, and an optical base 10 into which a part of each of the light projecting element and the light receiving element can be fitted. Yes. The detection unit 3 includes a heat sensing circuit (not shown) formed on the circuit board 4 for sensing heat and a heat sensing means (not shown) for sensing heat. For example, a thermistor or a bimetal may be employed as the heat sensing means.

  The light projecting element, the light receiving element, and the heat sensing means are mounted on the circuit board 4. The light projecting element and the light receiving element are mounted on the lower surface of the circuit board 4. Further, the heat sensing means is mounted on the lower surface of the circuit board 4 with a heat sensing portion (not shown) protruding downward.

  The optical base 10 is made of, for example, black synthetic resin, and integrally forms a plate-like (for example, disc-like) bottom plate 10a and a labyrinth wall 10b arranged on the lower surface side of the bottom plate 10a. Configured. The labyrinth wall 10b is composed of a plurality of partition walls having a substantially V-shaped horizontal cross section.

  The optical base 10 has a smoke sensing chamber A1 having a substantially circular horizontal cross section surrounded by a labyrinth wall 10b. In the fire detector of the present embodiment, the optical base 10 is formed of black synthetic resin, but it is only necessary to form it with a synthetic resin of a color that does not reflect light.

  The labyrinth wall 10b has a function of allowing the entrance of smoke from the outside into the smoke detection chamber A1 and preventing the incidence of external light into the smoke detection chamber A1.

  In addition, the optical base 10 has an opening window (not shown) formed at a portion facing each of the light projecting element and the light receiving element mounted on the lower surface of the circuit board 4, and the light is projected to one of the opening windows. Part of the element is fitted. In addition, the optical base 10 includes a first prism lens (not shown) that guides light emitted from a light projecting element partially fitted into one opening window to the smoke detection chamber A1, and a smoke detection chamber A1. A second prism lens (not shown) that guides the light inside to the light receiving element through the other opening window is provided.

  In the fire detector of the present embodiment, the light emitted from the light projecting element is collected by the first prism lens and applied to the smoke detection chamber A1. Here, in this fire detector, when smoke enters the smoke detection chamber A1, the scattered light from the smoke particles is collected by the second prism lens and irradiated to the light receiving element, so that the output of the light receiving element increases. Therefore, the smoke detection circuit in the fire detector of the present embodiment can detect the presence or absence of smoke based on the output of the light receiving element. Further, in the fire detector of the present embodiment, the detection circuit of the detection unit 3 can detect the occurrence of a fire based on the presence or absence of smoke by the smoke detection circuit.

  In the fire detector of the present embodiment, the optical axis of the first prism lens and the optical axis of the second prism lens are set to intersect at a predetermined angle. Thereby, in the fire detector of this embodiment, it can prevent that the light irradiated from the 1st prism lens irradiates the 2nd prism lens directly, and the smoke detection circuit detects the presence or absence of smoke. It becomes possible to improve.

  Further, the optical base 10 has a recess 10 c formed at a portion facing the heat sensing means mounted on the lower surface of the circuit board 4. At the bottom of the recess 10c, an insertion hole 10d for inserting the heat sensing part of the heat sensing means is provided.

  In addition, a bottomed cylindrical insect-proof cover 11 that prevents foreign substances such as insects from entering the smoke sensing chamber A1 is disposed on the outer peripheral portion of the labyrinth wall 10b. In other words, the labyrinth wall 10 b is stored in the insect-proof cover 11.

  The insect-proof cover 11 is formed of, for example, an insulating synthetic resin. Further, a mesh portion 12 having a plurality of vent holes 12a that are opened in a lattice shape is formed on the side wall 11b of the insect-proof cover 11. Moreover, the opening dimension of each ventilation hole 12a formed in the mesh part 12 is set to the dimension which prevents that foreign materials, such as an insect, penetrate | invade. Therefore, in the fire detector of this embodiment, the labyrinth wall 10b is housed in the insect-proof cover 11, and the side portion (smoke inlet) of the labyrinth wall 10b is covered with the mesh portion 12, so that the smoke detection of the optical base 10 is performed. Foreign matter can be prevented from entering the chamber A1.

  In addition, the bottom wall 11a of the insect-proof cover 11 is provided with an insertion hole 11e through which the heat sensing part of the heat sensing means is inserted at a portion facing the insertion hole 10d of the optical base 10.

  In addition, a hook 11c extending outward along the radial direction of the bottom wall 11a is formed at the upper end of the side wall 11b of the insect-proof cover 11. Engaging claws 11d protruding upward are provided at a plurality of locations (two locations in the illustrated example) on the outer peripheral portion of the flange portion 11c.

  The circuit board 4 is provided with an engaging portion 4a composed of a notch portion with which each engaging claw 11d of the collar portion 11c of the insect-proof cover 11 is engaged. Therefore, in the fire detector of the present embodiment, after the labyrinth wall 10b is housed in the insect-proof cover 11, each engagement claw 11d of the collar portion 11c of the insect-proof cover 11 is engaged with each engagement portion 4a of the circuit board 4. Thus, the insect-proof cover 11 is attached to the circuit board 4.

  The circuit board 4 is electrically connected with a plurality (four in the illustrated example) of connection terminals 18 that can be detachably connected to the connection terminal portions 17 of the base 1. Here, each connection terminal portion 17 of the base 1 is provided with a pair of clamping pieces 16 and 16 (see FIG. 9) capable of clamping each connection terminal 18 separately. In the present embodiment, four connection terminals 18 are provided. However, the present invention is not limited to this. For example, two connection terminals 18 may be provided.

  Each connection terminal 18 is formed by bending an elongated rectangular plate-like metal plate. Each connection terminal 18 is electrically connected to a terminal portion 18 d sandwiched between the pair of sandwiching pieces 16, 16 of the base 1 and a conductive pattern (not shown) formed on the upper surface of the circuit board 4. The fixing portion 18e has a U-shaped intermediate portion 18c that is connected to the terminal portion 18d and the fixing portion 18e and is inserted into the insertion hole 4b that is provided through the circuit board 4.

  The fixing portions 18 e of the connection terminals 18 are provided with first fixing screw insertion holes (not shown) through which the fixing screws 19 for fixing the connection terminals 18 to the circuit board 4 are inserted. . Here, the circuit board 4 has a second fixing screw insertion hole (not shown) through which the fixing screw 19 is inserted into a portion of the fixing portion 18e of each connection terminal 18 facing the first fixing screw insertion hole. Is provided.

  The light emitting element 6 is mounted on the periphery of the upper surface of the circuit board 4. In the fire detector of the present embodiment, a plurality (two in the illustrated example) of light emitting elements 6 are mounted on the circuit board 4.

  Each light emitting element 6 is turned on or off based on the presence or absence of the occurrence of a fire by the detection unit 3. That is, each light emitting element 6 is turned on when the detection unit 3 detects the occurrence of a fire. Here, in the fire detector of the present embodiment, each light emitting element 6 is turned on when the detection unit 3 detects the occurrence of a fire, but in addition to the lighting of each light emitting element 6, the occurrence of a fire May be transmitted to a fire alarm (not shown).

  The light guide 7 is an elongated plate-shaped molded product made of a transparent synthetic resin formed so that light from the light emitting element 6 enters from the incident surface 7a and exits from the output surface 7b, and the incident surface 7a has the incident surface 7a. The light emitting element 6 is optically coupled. In the fire detector of the present embodiment, the main body portion 2 includes a plurality (two in the illustrated example) of light guides 7.

  Each light guide 7 is formed with a reflection surface 7c that reflects the light incident from the incident surface 7a toward the exit surface 7b. In addition, each of the side surfaces of each light guide body 7 is provided with a protrusion 7 d for positioning the light guide body 7 on the body 5.

  The body 5 is formed of, for example, a synthetic resin, and has a bowl-shaped bottom wall 5a having an opening hole 5t at the center, a side wall 5b protruding upward from the outer periphery of the bottom wall 5a, and an opening hole 5t. And a bottomed cylindrical protective cover 5c that protrudes downward from the inner peripheral edge and protects the detection unit 3 and the insect-proof cover 11.

  On the inner bottom surface of the bottom wall 5a, fitting portions 20 for fitting the light guides 7 are provided at a plurality of locations (two locations in the illustrated example).

  Each insertion part 20 is comprised by the step part 20a for inserting the lower surface side of the light guide 7, and a pair of side-plate parts 20c and 20c formed so that the side surface of the light guide 7 might be opposed. Yes. Each side plate portion 20c is provided with an insertion groove 20b for inserting each projection 7d of the light guide 7 separately. Therefore, in the fire detector of this embodiment, the light guide 7 is positioned on the body 5 by inserting the two protrusions 7d of each light guide 7 into the respective insertion grooves 20b of the respective fitting portions 20 separately. The

  In addition, a window hole 5d that exposes the light exit surface 7b of the light guide 7 is provided in the bottom wall 5a so as to be opposed to the light exit surface 7b of the light guide 7 fitted in each fitting portion 20. Yes. Therefore, in the fire detector of the present embodiment, the emission surface 7b of the light guide 7 is exposed from the window hole 5d of the bottom wall 5a, so that the blinking state of the light emitting element 6 can be viewed from the outside of the body 5. Become.

  Moreover, the substantially cylindrical surrounding wall 21 which protrudes upwards is provided in the inner bottom face of the bottom wall 5a. The outer diameter of the peripheral wall 21 is set to be approximately the same as the outer diameter of the cover 8. Here, the peripheral wall 21 is configured by a semicircular arc-shaped first peripheral wall 21a in plan view and a semicircular arc-shaped second peripheral wall 21b in plan view. Moreover, the one end side of the 1st surrounding wall 21a and the 2nd surrounding wall 21b is connected with each side-plate part 20c of one fitting part 20, and the other end side of the 1st surrounding wall 21a and the 2nd surrounding wall 21b is the other fitting part 20. Are connected to each side plate portion 20c.

  By the way, in the fire detector of this embodiment, the cover 8 is disposed inside the side wall 5b of the body 5 so as to be separated from the side wall 5b and cover the opening hole 5t of the bottom wall 5a. Between the side wall 5b and the outer peripheral edge of the cover 8 on the upper surface side of the bottom wall 5a of the body 5, water adhering to the upper surface of the cover 8 (for example, water adhering to the upper surface of the cover 8 due to condensation or the base 1) A drain groove 22 is provided so as to surround the cover 8 in a plan view, for draining water that has fallen on the upper surface of the cover 8 from the wire connected to the wire connecting portion 13. In short, the body 5 is provided with a drain groove 22 for draining water adhering to the upper surface of the cover 8 so as to surround the cover 8. In the present embodiment, the drainage groove 22 is formed by the outer peripheral surface of the peripheral wall 21, the inner peripheral surface of the side wall 5b, the outer peripheral side of the peripheral wall 21 on the inner bottom surface of the bottom wall 5a, and the pair of side plate portions 20c and 20c of each fitting portion 20. (See FIG. 7). Here, the drainage groove 22 in the fire detector of the present embodiment is not provided so as to surround the cover 8 over the entire circumference of the outer peripheral edge of the cover 8 in plan view (except for the portions of the respective fitting portions 20). However, it may be provided so as to surround the cover 8 over the entire circumference.

  A drain hole 22 a through which water that has flowed into the drain groove 22 is drained to the outside of the body 5 is formed through the bottom of the drain groove 22 on the opening hole 5 t side. In short, a drain hole 22 a for draining water that has flowed into the drain groove 22 is provided at the bottom of the drain groove 22. In the fire detector of the present embodiment, a plurality (two in the illustrated example) of drain holes 22 a are provided in the drainage groove 22. Therefore, in the fire detector according to the present embodiment, water attached to the upper surface of the cover 8 can be drained from the drain hole 22a to the outside of the body 5 through the drainage groove 22.

  The inner diameter dimension of the side wall 5 b is set slightly larger than the outer diameter dimension of the side wall 1 b of the base 1.

  In the protective cover 5c, the detection unit 3 and the insect-proof cover 11 are accommodated. Here, the bottom plate 5f of the protective cover 5c is provided with a plurality of ribs 5g that come into contact with the bottom wall 11a of the insect-proof cover 11. That is, the heat sensing means in the fire detector of the present embodiment protrudes downward from the insertion hole 11e provided in the bottom wall 11a of the insect-proof cover 11, and the tip (heat sensing part) is in contact with the bottom wall 11a of the insect-proof cover 11. It arrange | positions between the bottom plates 5f of the protective cover 5c.

  A plurality of window holes 5j opened along the circumferential direction are formed in the side plate 5h of the protective cover 5c. The opening size of each window hole 5j is set larger than the opening size of each ventilation hole 12a formed in the mesh part 12 of the insect-proof cover 11. Therefore, in the heat detection circuit of the detection unit 3 in the fire detector of the present embodiment, air and smoke flowing into the body 5 from each window hole 5j of the protective cover 5c strike the heat detection unit of the heat detection means. Heat can be sensed through the sensing means. In the fire detector of the present embodiment, the detection circuit of the detection unit 3 can detect the occurrence of a fire based on the detection of heat by the heat detection circuit. Furthermore, in the fire detector of the present embodiment, the detection circuit can detect the occurrence of a fire based on the presence / absence of smoke by the smoke detection circuit and the detection of heat by the heat detection circuit. Thereby, in the fire detector according to the present embodiment, it is possible to improve the accuracy of detecting the occurrence of a fire as compared with one having either a smoke sensing function or a heat sensing function.

  The cover 8 is made of, for example, a white synthetic resin. In the fire detector of the present embodiment, the cover 8 is formed of white synthetic resin. However, the present invention is not limited to this. For example, the cover 8 is formed of synthetic resin having a color that is more likely to reflect light than black. Also good.

  On the upper surface side of the cover 8, an inclined portion 8 a that is inclined by a predetermined angle with respect to the construction surface is provided. In other words, the inclined portion 8a of the cover 8 is formed so as to descend from the center portion of the cover 8 toward the outer peripheral edge. That is, the inclined portion 8 a has a function of guiding water adhering to the upper surface of the cover 8 due to condensation to the drain groove 22 of the body 5. Therefore, in the fire detector according to the present embodiment, it is possible to suppress water from staying on the upper surface side of the cover 8 by providing the inclined portion 8 a on the upper surface side of the cover 8.

  Further, the cover 8 has a chamfered portion 8 b formed at a portion where the upper surface side of the cover 8 and the outer peripheral edge of the cover 8 are connected. Therefore, in the fire detector according to the present embodiment, by providing the cover 8 with the chamfered portion 8b, water attached to the upper surface of the cover 8 can easily flow down from the inclined portion 8a to the drain groove 22 and Can be further suppressed. Further, in the fire detector of the present embodiment, the chamfered portion 8 b is provided in the cover 8 to suppress the water that has flowed into the drainage groove 22 from returning to the upper surface side of the cover 8 due to the surface tension in the drainage groove 22. This makes it possible to suppress water from staying on the upper surface side of the cover 8.

  Further, on the upper surface of the cover 8, projecting base portions 8 c that protrude upward are provided at portions corresponding to the connection terminals 18 that are electrically connected to the circuit board 4. An insertion hole 8d through which each connection terminal 18 is inserted from the lower surface side of the cover 8 is provided through each of the projecting portions 8c. Thereby, in the fire detector of this embodiment, each connection terminal 18 electrically connected to the circuit board 4 protrudes outside the main body 2 through the insertion hole 8 d of the cover 8. Moreover, in this embodiment, since each insertion hole 8d is provided in the protrusion part 8c, it becomes possible to suppress that the water generated on the upper surface of the cover 8 adheres to each connection terminal 18.

  On the lower surface of the cover 8, a rectangular tube-shaped tube portion 8 f that covers the side portion of each connection terminal 18 faces downward in each portion corresponding to each connection terminal 18 electrically connected to the circuit board 4. Projected. The opening size of each cylindrical portion 8 f is set smaller than the opening size of each insertion hole 4 b of the circuit board 4. A positioning projection 27 for positioning the circuit board 4 on the cover 8 is provided on the lower surface of the cover 8. Here, on the outer peripheral edge of the circuit board 4, a notch portion 4 c through which the positioning protrusion 27 is inserted is provided at a portion corresponding to the positioning protrusion 27 of the cover 8.

  Further, on the body 5 side of the cover 8, fixing screw holes 8 h into which the fixing screws 19 are screwed are provided in portions corresponding to the respective second fixing screw insertion holes of the circuit board 4. In addition, a plurality of (two in the illustrated example) ribs 8g are provided at the central portion of the lower surface of the cover 8 so that the tip portion protrudes downward and contacts the circuit board 4. Therefore, in the fire detector according to the present embodiment, the fixing screw 19 is inserted from the lower surface side of the circuit board 4 into the second fixing screw insertion hole and the first fixing screw insertion hole of the connection terminal 18 to fix the cover 8. The connection terminals 18 are fixed to the circuit board 4 and screwed into the screw holes 8h, and the circuit board 4 is attached to the cover 8. Here, on the cover 8 side of the bottom wall 5a of the body 5, a recess 5q for accommodating the screw head of the fixing screw 19 is provided in each of the portions corresponding to the second fixing screw insertion hole of the circuit board 4. ing.

  Further, on the upper surface of the cover 8, it is arranged on the side portion of the two connection terminals 18, 18 among the connection terminals 18 that pass through the respective insertion holes 8 d of the cover 8 and protrude to the outside of the main body 2. In addition, a pair of wall portions 23, 23 are provided to prevent water generated on the upper surface of the cover 8 from flowing along the upper surface of the inclined portion 8 a and adhering to the connection terminals 18. The height dimension of a pair of wall parts 23 and 23 is set larger than the height dimension of the protruding base part 8c. Therefore, in the fire detector of the present embodiment, by providing the pair of wall portions 23, 23 on the upper surface of the cover 8, it is possible to suppress the water generated on the upper surface of the cover 8 from adhering to each connection terminal 18. It becomes possible.

  By the way, in the fire detector according to the present embodiment, the inclined portion 8a of the cover 8 and the pair of wall portions 23 and 23 guide the water generated on the upper surface of the cover 8 due to condensation to the drain groove 22 of the body 5. A path 24 is formed. Thereby, in the fire detector of this embodiment, compared with the case where only the inclined portion 8 a is provided on the upper surface side of the cover 8, it is possible to further suppress water from staying on the upper surface side of the cover 8. .

  At the periphery of the cover 8, the cover 8 is engaged with the engaging claw 8 j that is engaged with the side wall 5 b of the body 5 so as to cover the opening hole 5 t of the bottom wall 5 a inside the side wall 5 b of the body 5 and away from the side wall 5 b. Are provided at a plurality of locations (two locations in the illustrated example). Here, on the inner peripheral surface of the side wall 5 b of the body 5, a locking portion 5 e that locks each locking claw 8 j of the cover 8 protrudes. Therefore, in the fire detector of the present embodiment, the cover 8 is locked to the side wall 5b of the body 5 by locking each locking claw 8j of the cover 8 to each locking portion 5e of the side wall 5b of the body 5. It arrange | positions so that it may be separated from the side wall 5b inside, and the opening hole 5t of the bottom wall 5a may be covered. In short, the cover 8 is attached to the body 5.

  Further, guide pieces 8k for attaching the cover 8 to the body 5 are provided at a plurality of locations (four locations in the illustrated example) around the periphery of the cover 8. Here, in the drainage groove 22 of the body 5, a guide portion 25 into which each guide piece 8 k of the cover 8 can be inserted and removed is formed. Each guide portion 25 is provided with an insertion groove 25a for inserting each guide piece 8k of the cover 8 separately.

  Further, a protrusion 8 m that can be elastically deformed in the thickness direction of the cover 8 is provided on the periphery of the cover 8 at a portion facing the light guide 7 when attached to the body 5. Each protruding piece 8m extends outward from the peripheral portion of the cover 8 along the radial direction of the cover 8.

  On the body 5 side of each projecting piece 8m, a projecting portion 9 that faces the reflecting surface 7c of the light guide 7 is formed.

  Each protrusion 9 is provided with an inclined surface 9 a at a portion facing the reflecting surface 7 c of the light guide 7. These inclined surfaces 9 a are designed so that a gap between the light guide 7 and the reflecting surface 7 c is small when the cover 8 is attached to the body 5.

  In the fire detector of the present embodiment, when the cover 8 is attached to the body 5, first, a part of each guide piece 8 k of the cover 8 is separately inserted into the insertion groove 25 a of each guide portion 25 of the body 5. At this time, the protrusions 8m of the cover 8 are elastically deformed upward because the protrusions 9 abut against the bottom wall 5a of the body 5 on the outer peripheral side of the peripheral wall 21 of the body 5. When the guide pieces 8k of the cover 8 are inserted into the insertion grooves 25a of the guide portions 25 of the body 5, the locking claws 8j of the cover 8 are respectively inserted into the locking portions 5e of the body 5. In addition to being locked, a downward restoring force acts on the tip of each protrusion piece 8m, and each protrusion is made to reduce the gap between the inclined surface 9a of the protrusion 9 and the reflecting surface 7c of the light guide 7. It returns to the state before the piece 8m is elastically deformed. Therefore, in the fire detector of the present embodiment, when the cover 8 is attached to the body 5, the gap between the inclined surface 9a of the protrusion 9 and the reflecting surface 7c of the light guide 7 is reduced. Light leakage generated from the reflection surface 7c of each light guide 7 can be suppressed, and a reduction in the luminance of light emitted from the emission surface 7b of the light guide 7 can be suppressed. Here, the pair of side plate portions 20c, 20c of each fitting portion 20 prevents each protrusion 9 from rotating along the circumferential direction of the cover 8 when the cover 8 is attached to the body 5. It is formed to do. In short, each fitting portion 20 of the body 5 has a stopper function for restricting the rotation of the cover 8. In the fire detector of the present embodiment, when the cover 8 is attached to the body 5, the gap between the inclined surface 9a of the protrusion 9 and the reflecting surface 7c of the light guide 7 is made small. However, the present invention is not limited to this, and for example, the inclined surface 9a of the protrusion 9 and the reflecting surface 7c of the light guide 7 may contact each other.

  Further, in the fire detector of the present embodiment, a plurality of first locking protrusions 5k that lock the main body 2 to the base 1 are provided at a plurality of locations (three locations in the illustrated example) on the inner peripheral surface of the side wall 5b of the body 5. Is provided. Moreover, the 2nd latching protrusion 5m which latches the main-body part 2 to the base 1 is provided in multiple places (in the example of illustration, two places) on the internal peripheral surface of the side wall 5b. Further, a third locking projection 5n (see FIG. 5) for locking the main body 2 to the base 1 is provided on the inner peripheral surface of the side wall 5b. Here, the outer peripheral surface of the side wall 1b of the base 1 is provided with first locking holes 1e (see FIG. 9) for locking the first locking projections 5k on the side wall 5b of the body 5. Further, on the outer peripheral surface of the side wall 1 b of the base 1, second locking holes 1 f (see FIG. 9) for locking the second locking protrusions 5 m on the side wall 5 b of the body 5 are provided. A third locking hole 1g (see FIG. 9) for locking the third locking protrusion 5n on the side wall 5b of the body 5 is provided on the outer peripheral surface of the side wall 1b of the base 1. Therefore, in the fire detector of the present embodiment, the locking projections 5k, 5m, and 5n of the side wall 5b of the body 5 are locked to the locking holes 1e, 1f, and 1g of the side wall 1b of the base 1, respectively. The main body 2 is attached to the base 1.

  By the way, in the above-mentioned fire detector, it is possible to suppress water from staying on the upper surface side of the cover 8 by providing the inclined portion 8 a on the upper surface side of the cover 8 and providing the chamfered portion 8 b on the cover 8. Although it becomes possible, when the below-mentioned drawing-in part 26 is not provided, the water which flowed down into the drainage groove 22 of the body 5 may stay in the location of the drainage groove 22 surrounded by the one-dot chain line in FIG. .

  Therefore, in the fire detector according to the present embodiment, a lead-in portion 26 that draws water that has flowed into the drainage groove 22 into the drainage hole 22a by capillary action is provided over the entire circumference of the drainage groove 22 on the opening hole 5t side. . In short, in the present embodiment, the lead-in part 26 is provided over the entire circumference of the drainage groove 22. In this embodiment, the space enclosed by the outer peripheral part of the cover 8, the peripheral wall 21, and the outer peripheral side of the peripheral wall 21 in the bottom wall 5a comprises the drawing-in part 26 (refer FIG.1 (b)). Here, a projecting piece 8 e that protrudes downward is provided on the outer peripheral portion of the cover 8. In the present embodiment, the distance between the front end surface of the projecting piece 8 e and the inner bottom surface of the drainage groove 22 is set so that the cover 8 is attached to the body 5. Further, a recess 28 is provided over the entire circumference of the drain groove 22 on the opening hole 5 t side on the opening hole 5 t side in the bottom of the drain groove 22. In the present embodiment, when the cover 8 is attached to the body 5, the distance between the inner bottom surface of the recess 28 and the lower surface of the cover 8 is between the front end surface of the projecting piece 8 e and the inner bottom surface of the drainage groove 22. It is set to be larger than the distance.

  Thus, according to the fire sensor of the present embodiment, the body 5 is provided with the drain groove 22 for draining the water adhering to the upper surface of the cover 8 so as to surround the cover 8, and the drain groove 22. A drain hole 22a for draining water that has flowed into the drain groove 22 is provided at the bottom of the drain, and the water that has flowed into the drain groove 22 over the entire circumference of the drain groove 22 is drawn into the drain hole 22a by capillary action. Since the portion 26 is provided, it is possible to suppress water from staying in the drain groove 22 and to suppress water from staying in the main body portion 2. Further, in the present embodiment, the bottom wall 5a of the body 5 is formed in a bowl shape, and a drain hole 22a is provided on the opening hole 5t side of the bottom of the drainage groove 22, and the drainage groove 22 is on the opening hole 5t side. Since the lead-in portion 26 is provided over the entire circumference of the drainage groove 22, the water that has flowed into the drainage groove 22 is drained from the drainage hole 22 as compared with the case where the drainage hole 22 a is provided on the drainage groove 22 other than the opening hole 5 t side. It becomes easy to pull in. Thereby, in this embodiment, it becomes possible to further suppress that water retains in the drain groove 22, and it becomes possible to further suppress that water retains in the main-body part 2. FIG. In the present embodiment, the distance between the tip surface of the projecting piece 8 e and the inner bottom surface of the drainage groove 22 is set to be smaller than the distance between the inner bottom surface of the recess 28 and the lower surface of the cover 8. Therefore, compared with the case where the protrusion 8 e is not provided on the outer peripheral portion of the cover 8, the water that has flowed into the drainage groove 22 is easily drawn into the drainage hole 22.

  In addition, although the fire detector of this embodiment has a smoke detection function and a heat detection function, it is not limited to this. For example, it may have only a smoke detection function or a heat detection function. It may have a flame sensing function for sensing flame.

2 Body part 3 Detection part 5 Body 8 Cover 22 Drainage groove 22a Drain hole 26 Lead-in part

Claims (1)

  A fire detector including a detection unit that detects the occurrence of a fire, a body that houses the detection unit, and a plate-like cover that is attached to the body, wherein the body includes: A drainage groove for draining water adhering to the upper surface of the cover is provided so as to surround the cover, and a drain hole for draining water that has flowed into the drainage groove is provided at the bottom of the drainage groove, A fire sensor, wherein a lead-in portion for drawing water that has flowed into the drainage groove into the drainage hole by capillary action is provided over the entire circumference of the drainage groove.

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