JP5810444B2

JP5810444B2 - smoke detector

Info

Publication number: JP5810444B2
Application number: JP2011190940A
Authority: JP
Inventors: 大明樋口
Original assignee: New Cosmos Electric Co Ltd
Current assignee: New Cosmos Electric Co Ltd
Priority date: 2011-09-01
Filing date: 2011-09-01
Publication date: 2015-11-11
Anticipated expiration: 2031-09-01
Also published as: JP2013054455A

Description

本発明は、正面視円形状の煙感知器に関する。 The present invention relates to a smoke detector having a circular shape when viewed from the front.

近年、煙感知器について、検知性能の向上だけでなく、外観デザインの向上にも開発力が注がれている。例えば、特許文献１に記載の煙感知器（熱煙複合式感知器）は、正面視円形状、かつ、側面視における正面側（取付面と反対側）の形状が略円弧形状、即ち、全体として、球面の一部を切り取ったような形状に形成してある。このような外観デザインであると、正面視四角形状のものや、正面視円形状かつ側面視ダルマ形状（煙センサ部分が正面側へ突出している形状）のようなものと比較して、全体としてスマートな印象を与える。 In recent years, with regard to smoke detectors, not only the improvement of detection performance but also the development power has been put into improving the appearance design. For example, the smoke detector (thermal smoke combined sensor) described in Patent Document 1 has a circular shape when viewed from the front, and the shape of the front side (opposite to the mounting surface) when viewed from the side is a substantially arc shape, that is, the whole As shown in FIG. Compared to such an external design such as a square shape when viewed from the front, or a circular shape when viewed from the front and a dharma shape when viewed from the side (a shape in which the smoke sensor portion protrudes to the front side), as a whole Give a smart impression.

特開２００１−２６６２６５号公報JP 2001-266265 A

ところで、煙にはある程度の流速があり、障害物に対してその形状に沿って流れる傾向がある。しかし、特許文献１に記載の煙感知器は、本体ケースの内部空間に、煙センサ（文献では、「ラビリンス体」、「防虫メッシュ」、及び、「光学素子部」）を収容し、本体ケースの外周回りに、周方向に沿って煙流入用の流入孔を開口してある。つまり、球面状に連続する面に流入口、周方向に流入口を設けた形状である。このため、特許文献１に記載のような煙感知器であると、煙が煙感知器の外形（球面形状）に沿って流れてしまい、煙流入口を通り過ぎ、煙が煙感知器内部に流入し難くなる虞がある。このような場合、煙の感知が遅れたり、煙の濃度を正確に感知できなかったりする可能性がある。 By the way, smoke has a certain flow rate and tends to flow along its shape with respect to an obstacle. However, the smoke detector described in Patent Document 1 accommodates a smoke sensor (in the literature, “labyrinth body”, “insect repellent mesh”, and “optical element portion”) in the internal space of the main body case. An inflow hole for inflow of smoke is opened along the circumferential direction around the outer periphery of the. That is, it is a shape in which an inlet is provided on a spherical continuous surface and an inlet is provided in the circumferential direction. For this reason, in the smoke detector as described in Patent Document 1, smoke flows along the outer shape (spherical shape) of the smoke detector, passes through the smoke inlet, and smoke flows into the smoke detector. There is a risk of difficulty. In such a case, the detection of smoke may be delayed, or the smoke concentration may not be detected accurately.

上記実情を鑑み、本発明は、外観デザインを向上しつつも、感知性能を向上させる煙感知器を提供することを目的とする。 In view of the above circumstances, an object of the present invention is to provide a smoke detector that improves the sensing performance while improving the appearance design.

本発明に係る煙感知器の第一特徴構成は、正面視円形状、かつ、側面視における正面側の形状が略円弧形状の煙感知器であって、正面視円形状であり、かつ、正面中央部分を、径内方向に向うに従って背面側に近付くように凹入して形成した凹入部、及び、前記凹入部と隣り合う正面外周部分を、径外方向に向うに従って背面側に近付くように傾斜させて形成した傾斜部を有するハウジングと、前記凹入部から正面側に突出する状態で、前記ハウジングに支持された煙センサと、正面視円形状であり、前記凹入部に対して離間した状態で対向するように前記ハウジングの正面側に支持されて、前記煙センサを正面側から覆い込むと共に、前記凹入部と協働して、前記煙センサに煙を誘導する煙流路を構成する前カバーと、を備え、前記前カバーに、前記前カバーの外周部の全周に亘って、前記凹入部と前記傾斜部との境界よりも径外方向に突出する鍔部を備えると共に、外周側から前記煙センサ側に向うに従って前記前カバーと前記凹入部とが離間し、前記煙流路が広がるように構成してある点にある。 The first characteristic configuration of the smoke detector according to the present invention is a smoke detector having a circular shape when viewed from the front and a substantially arc-shaped shape when viewed from the side, and having a circular shape when viewed from the front. The concave portion formed by recessing the central portion so as to approach the back side as it goes in the radial direction, and the front outer peripheral portion adjacent to the concave portion so as to approach the back side as it goes in the radial direction A housing having an inclined portion formed by inclining, a smoke sensor supported by the housing in a state protruding from the recessed portion to the front side, and a circular shape when viewed from the front, separated from the recessed portion The smoke sensor is supported by the front side of the housing so as to face each other, covers the smoke sensor from the front side, and cooperates with the recessed portion to form a smoke flow path for inducing smoke to the smoke sensor. And a front cover. And provided with a flange projecting radially outward from the boundary between the recessed portion and the inclined portion over the entire circumference of the outer peripheral portion of the front cover, and further toward the smoke sensor side from the outer peripheral side. The front cover and the recessed portion are separated from each other, and the smoke flow path is widened.

本特徴構成のように、煙感知器を、正面視円形状、かつ、側面視における正面側の形状が略円弧形状に構成することで、スマートな印象を与えられると共に、ハウジングに設けた凹入部に煙センサを配設することで、煙センサのハウジングからの突出量を少なく抑えられ、薄型の煙感知器とすることができる。 Like this feature configuration, the smoke detector has a circular shape when viewed from the front, and the shape of the front side when viewed from the side is a substantially arc shape, giving a smart impression and a recessed portion provided in the housing. By disposing the smoke sensor in the housing, the amount of protrusion from the housing of the smoke sensor can be suppressed to a small level, and a thin smoke detector can be obtained.

また、本構成によると、ハウジングに傾斜部を備えると共に、前カバーに、前カバーの外周部の全周に亘って凹入部と傾斜部との境界よりも径外方向に突出する鍔部を備えている。したがって、例えば、取付面に沿って流れてきた煙は、傾斜部によってハウジングの形状に沿って取付面（天上面）側から正面側に誘導される。その後、煙は、鍔部にぶつかり、そのまま流れ去ることなく円滑に煙流路に流入する。さらに、本構成であれば、煙流路が、外周側（入り口側）から煙センサに近付くに従って広がっているので、煙は、何れかの方向から煙流路に一旦入りさえすれば、内部の広い空間で煙センサの外周回りに万遍なく拡散され、煙の流れ方向にあまり影響を受けることなく、適切かつ円滑に煙センサにまで到達する。これらの結果、確実に煙を感知することが可能となる。 Further, according to this configuration, the housing includes the inclined portion, and the front cover includes the flange portion that protrudes radially outward from the boundary between the recessed portion and the inclined portion over the entire circumference of the outer peripheral portion of the front cover. ing. Therefore, for example, smoke flowing along the mounting surface is guided from the mounting surface (top surface) side to the front side along the shape of the housing by the inclined portion. Thereafter, the smoke collides with the buttocks and smoothly flows into the smoke flow path without flowing away. Furthermore, with this configuration, the smoke flow path spreads as it approaches the smoke sensor from the outer peripheral side (entrance side), so that the smoke once enters the smoke flow path from any direction. It diffuses evenly around the outer circumference of the smoke sensor in a wide space, and reaches the smoke sensor appropriately and smoothly without being greatly affected by the direction of smoke flow. As a result, smoke can be reliably detected.

つまり、本構成であれば、側面視では鍔部の突出分だけ円弧形状から若干遠ざかる外観とはなるものの、略円弧形状であるので、デザインの向上が図られ、その他の構成により、煙感知性能を向上させられる。 In other words, with this configuration, although the appearance is slightly distant from the arc shape by the amount of protrusion of the buttock in the side view, the design is improved due to the substantially arc shape, and smoke detection performance is achieved by other configurations. Can be improved.

本発明に係る煙感知器の第二特徴構成は、前記前カバーの正面中央部分は、正面側へ膨出する形状であり、かつ、前記前カバーのうち最も正面側に膨出した部分は、前記傾斜部を径内方向に延長して得られる面よりも、前記凹入部の側に位置する点にある。 The second characteristic configuration of the smoke detector according to the present invention is that the front center portion of the front cover has a shape that bulges to the front side, and the portion that bulges to the most front side of the front cover is: It exists in the point located in the said recessed part side rather than the surface obtained by extending the said inclination part in radial direction.

本特徴構成であると、前カバーのうち最も正面側に膨出した部分が、傾斜部を径内方向に延長して得られる面よりも、凹入部の側に位置するので、前カバーの側面視における厚みが薄くなって、ハウジングに対する存在感が小さくなると共に、傾斜部と前カバーとの連続感が演出される。よって、鍔部の突出が目立たなくなると共に、煙感知器全体としても薄型のものとなって、外観デザインが向上する。 In this feature configuration, the portion of the front cover that bulges to the most front side is located closer to the recessed portion than the surface obtained by extending the inclined portion radially inward. The visual thickness is reduced, the presence of the housing is reduced, and a continuous feeling between the inclined portion and the front cover is produced. Therefore, the protrusion of the heel portion becomes inconspicuous, and the smoke detector as a whole becomes thin so that the appearance design is improved.

本発明に係る煙感知器の第三特徴構成は、前記煙センサは、発光部と受光部とを備えた光電式のセンサであり、前記前カバーを、前記前カバーまたは前記ハウジングに備えられた支持部によって前記ハウジングの正面側に支持し、前記支持部を、正面視で、前記発光部の近傍または前記受光部の近傍に位置させてある点にある。 A third characteristic configuration of the smoke detector according to the present invention is that the smoke sensor is a photoelectric sensor including a light emitting unit and a light receiving unit, and the front cover is provided in the front cover or the housing. The support portion is supported on the front side of the housing, and the support portion is located in the vicinity of the light emitting portion or the light receiving portion in a front view.

本特徴構成によると、支持部が、そもそも煙の入り口がない発光部の近傍または受光部の近傍に位置するので、煙センサへの煙の流入が阻害されにくい。 According to this characteristic configuration, since the support portion is located in the vicinity of the light emitting portion or the light receiving portion where there is no smoke entrance, the inflow of smoke to the smoke sensor is not easily inhibited.

本発明に係る煙感知器の斜視図である。1 is a perspective view of a smoke detector according to the present invention. 天井面に取り付けた状態の煙感知器の側面図である。It is a side view of the smoke detector of the state attached to the ceiling surface. 煙感知器の正面図である。It is a front view of a smoke detector. 煙感知器の背面図である。It is a rear view of a smoke sensor. 正面側から観た煙感知器の分解斜視図である。It is a disassembled perspective view of the smoke detector seen from the front side. 背面側から観た煙感知器の分解斜視図である。It is a disassembled perspective view of the smoke detector seen from the back side. 図３におけるＶＩＩ−ＶＩＩ方向の断面図である。It is sectional drawing of the VII-VII direction in FIG. 導入凹部及び収納凹部付近の背面図である。It is a rear view of the vicinity of the introduction recess and the storage recess. 収納凹部の断面斜視図である。It is a cross-sectional perspective view of a storage recessed part. 図８におけるＸ−Ｘ方向の断面図である。It is sectional drawing of the XX direction in FIG. 煙感知器の煙検知性能に関する実証データを示すグラフである。It is a graph which shows the demonstration data regarding the smoke detection performance of a smoke detector.

以下に、本発明の実施形態を図面に基づいて説明する。 Embodiments of the present invention will be described below with reference to the drawings.

〔全体構成について〕
煙感知器は、煙センサ４（図５及び図６参照）、不図示のＣＯセンサ及び不図示のガスセンサを備えており、天井面Ｃに取り付けられて、煙の発生と一酸化炭素ガスの発生、及び、都市ガス等のガス漏れ、を検知可能な複合型の煙感知器である。また、煙センサ４は、正面視円形状であって、内部に発光部４２と受光部４３とを備えた光学式のセンサである。以下、天井面Ｃに煙感知器を取り付けた状態において、天井面Ｃの側となる側を「裏面」，「後」，「背面」等と称し、天井面Ｃと反対側となる側を「表面」，「前」，「正面」等と称する。天井面Ｃに取り付けられるものであるので、正面視で上下の区別は特にない。 [About overall configuration]
The smoke detector includes a smoke sensor 4 (see FIGS. 5 and 6), a CO sensor (not shown), and a gas sensor (not shown), and is attached to the ceiling surface C to generate smoke and carbon monoxide gas. And a smoke detector that can detect gas leaks such as city gas. The smoke sensor 4 is an optical sensor having a circular shape when viewed from the front and having a light emitting unit 42 and a light receiving unit 43 therein. Hereinafter, in a state in which the smoke detector is attached to the ceiling surface C, the side that becomes the side of the ceiling surface C is referred to as “back surface”, “rear”, “back surface”, and the side that is opposite to the ceiling surface C is “ Called “front”, “front”, “front”, etc. Since it is attached to the ceiling surface C, there is no particular distinction between upper and lower in a front view.

煙感知器は、図１乃至図３に示すごとく、正面視で円形状であり、側面視で正面側の外形状が略円弧形状である。煙感知器は、煙センサ４、ＣＯセンサ、及び、ガスセンサが内装された「ハウジング」としてのフロントケース１を備えている。フロントケース１の背面側はリアケース２によって形成されている。フロントケース１及びリアケース２は、樹脂製であって、射出成形によって形成してある。フロントケース１及びリアケース２は、図３及び図４に示すごとく、正面視円形状である。 As shown in FIGS. 1 to 3, the smoke detector has a circular shape when viewed from the front, and an outer shape on the front side when viewed from the side is a substantially arc shape. The smoke detector includes a front case 1 as a “housing” in which a smoke sensor 4, a CO sensor, and a gas sensor are housed. The rear side of the front case 1 is formed by the rear case 2. The front case 1 and the rear case 2 are made of resin and are formed by injection molding. As shown in FIGS. 3 and 4, the front case 1 and the rear case 2 have a circular shape when viewed from the front.

〔フロントケース及びリアケースについて〕
フロントケース１は、図５乃至図７に示すごとく、正面中央部分を背面側に凹入した凹入部１５と、凹入部１５と隣り合う正面外周部分である傾斜部１６と、を備えている。凹入部１５は、径内方向に向うに従って背面側に近付くように、背面側へ膨出する球面状に凹入してある。傾斜部１６は、径外方向に向うに従って背面側に近付くように、球面状に傾斜させてある。即ち、傾斜部１６は、正面側に膨出する球面から、背面側に膨出する球面（凹入部１５）を差し引いた形状となっている。図５及び図７に示すごとく、傾斜部１６の背面側の端部から背面側に向けて筒状に立上り部分を設けてある。この立上り部分の背面側の端部にリアケース２を嵌め込む。 [About front case and rear case]
As shown in FIGS. 5 to 7, the front case 1 includes a recessed portion 15 in which a front center portion is recessed on the back side, and an inclined portion 16 that is a front outer peripheral portion adjacent to the recessed portion 15. The recessed portion 15 is recessed in a spherical shape that bulges to the back side so as to approach the back side as it goes in the radially inward direction. The inclined portion 16 is inclined in a spherical shape so as to approach the back side as it goes in the radially outward direction. That is, the inclined portion 16 has a shape obtained by subtracting a spherical surface (recessed portion 15) bulging to the back side from a spherical surface bulging to the front side. As shown in FIGS. 5 and 7, a rising portion is provided in a cylindrical shape from an end portion on the back side of the inclined portion 16 toward the back side. The rear case 2 is fitted into the end of the rising portion on the back side.

図６及び図７に示すごとく、フロントケース１の背面側（煙感知器内部側）には、背面側へ立ち上げられた連続壁であるスピーカ収容部１１やセンサ収容部１２等を備えている。スピーカ収容部１１は、フロントケース１とリアケース２とを組付けたとき（以下、単に「組付け時」と称する）に、リアケース２の正面側（煙感知器内部側）に形成されたスピーカ収容部２８（図５参照）と協働して不図示のスピーカを収容する空間を構成する。同様に、センサ収容部１２は、フロントケース１とリアケース２とを組付けたときに、リアケース２の正面側（煙感知器内部側）に形成されたセンサ収容部２９（図５参照）と協働してＣＯセンサ及びガスセンサを収容する空間を構成する。リアケース２も、樹脂製であって、射出成形によって形成してある。 As shown in FIGS. 6 and 7, the back side of the front case 1 (inside the smoke detector) includes a speaker housing part 11, a sensor housing part 12, and the like that are continuous walls raised to the back side. . The speaker housing 11 is formed on the front side of the rear case 2 (inside the smoke detector) when the front case 1 and the rear case 2 are assembled (hereinafter simply referred to as “when assembled”). A space for housing a speaker (not shown) is configured in cooperation with the speaker housing portion 28 (see FIG. 5). Similarly, when the front case 1 and the rear case 2 are assembled, the sensor housing part 12 is formed on the front side of the rear case 2 (inside the smoke detector) (see FIG. 5). The space which accommodates a CO sensor and a gas sensor is comprised in cooperation with. The rear case 2 is also made of resin and is formed by injection molding.

図５及び図７に示すごとく、リアケース２の正面側に、複数の筒状の基板取付ボス部２６を備えている。予め煙センサ４を固定した基板５を、基板取付ボス部２６の先端部に載置し、正面側からネジ等を締め込んで、基板５をリアケース２に固定する。基板取付ボス部２６の位置及び基板５の正面視形状は、基板５を固定したときに煙センサ４が正面視でリアケース２の中心部分に位置するように、設定してある。 As shown in FIGS. 5 and 7, a plurality of cylindrical substrate mounting boss portions 26 are provided on the front side of the rear case 2. The substrate 5 to which the smoke sensor 4 is fixed in advance is placed on the tip of the substrate mounting boss portion 26, and screws or the like are tightened from the front side to fix the substrate 5 to the rear case 2. The position of the board mounting boss portion 26 and the front view shape of the board 5 are set so that the smoke sensor 4 is located at the center of the rear case 2 in front view when the board 5 is fixed.

図５乃至図７に示すごとく、凹入部１５の中心部分（径内側部分）には、正面視円形状である煙センサ４の円形状に対応させて円形状の開口１５ａを設けてある。また、図６に示すごとく、フロントケース１の背面側には、複数の筒状のフロントボス部１７を備えている。さらに、図５に示すごとく、リアケース２の正面側のうち組付け時にフロントボス部１７に対応する位置に、複数の筒状のリアボス部２７を備えている。 As shown in FIGS. 5 to 7, a circular opening 15 a is provided in the central portion (diameter inner portion) of the recessed portion 15 so as to correspond to the circular shape of the smoke sensor 4 that is circular when viewed from the front. Further, as shown in FIG. 6, a plurality of cylindrical front boss portions 17 are provided on the back side of the front case 1. Further, as shown in FIG. 5, a plurality of cylindrical rear boss portions 27 are provided at positions corresponding to the front boss portions 17 when assembled on the front side of the rear case 2.

組付け時には、基板５を取り付けた状態のリアケース２に対して、スピーカ収容部２８にスピーカを収容し、センサ収容部２９にＣＯセンサ及びガスセンサを収容する。そして、フロントケース１とリアケース２とを位置合わせすると、図７に示すごとく、フロントボス部１７の先端面とリアボス部２７の先端面とが同位置になるので、リアケース２の側からネジ等を締め込んで、フロントケース１とリアケース２とを固結する。 At the time of assembly, a speaker is accommodated in the speaker accommodating portion 28 and a CO sensor and a gas sensor are accommodated in the sensor accommodating portion 29 with respect to the rear case 2 with the substrate 5 attached. When the front case 1 and the rear case 2 are aligned, the front end surface of the front boss portion 17 and the front end surface of the rear boss portion 27 are in the same position as shown in FIG. Etc. are tightened, and the front case 1 and the rear case 2 are consolidated.

このとき、煙センサ４が開口１５ａを貫通し、煙センサ４が正面側に露出される。詳しくは、図７に示すごとく、側面視において、煙センサ４の煙導入口４１のうち背面側の端部は、開口部１５ａと略同位置となる。また、煙センサ４の正面側の面は、「凹入部１５と傾斜部１６との境界」である境界ラインｂよりも、正面側に突出している。即ち、側面視において、少なくとも煙導入口４１の全てが開口部１５ａよりも正面側に露出し、かつ、煙導入口４１の背面側の一部が境界ラインｂよりも背面側に引退している状態となっている。なお、境界ラインｂは、フロントケース１において最も正面側に位置する環状の境界線を示すこととなる。 At this time, the smoke sensor 4 penetrates the opening 15a, and the smoke sensor 4 is exposed to the front side. Specifically, as shown in FIG. 7, in the side view, the end on the back side of the smoke introduction port 41 of the smoke sensor 4 is substantially at the same position as the opening 15 a. Further, the surface on the front side of the smoke sensor 4 protrudes more on the front side than the boundary line b which is “the boundary between the recessed portion 15 and the inclined portion 16”. That is, in side view, at least all of the smoke inlet 41 is exposed to the front side of the opening 15a, and a part of the rear side of the smoke inlet 41 is retreated to the back side of the boundary line b. It is in a state. Note that the boundary line b indicates an annular boundary line located on the most front side in the front case 1.

〔トップカバーについて〕
図５乃至図７に示すごとく、リアケース２が組付けられたフロントケース１に対して、正面側から、「前カバー」としてのトップカバー３を取り付ける。トップカバー３は正面視円形状に形成してある。トップカバー３の背面側に十字形状に形成された当たり部（図６参照）が、煙センサ４の正面側の面に当接して、トップカバー３は、凹入部１５に対して離間した状態で対向するように位置決めされる。 [About the top cover]
As shown in FIGS. 5 to 7, a top cover 3 as a “front cover” is attached to the front case 1 with the rear case 2 assembled from the front side. The top cover 3 is formed in a circular shape when viewed from the front. A contact portion (see FIG. 6) formed in a cross shape on the back side of the top cover 3 is in contact with the surface on the front side of the smoke sensor 4, and the top cover 3 is separated from the recessed portion 15. Positioned to face each other.

トップカバー３の背面側には、図６に示すごとく、周方向に沿って均等に配置された「支持部」としての支持脚３１を四箇所備えている。そして、フロントケース１のうち支持脚３１の位置に対応する位置に係止孔１８を四箇所形成してある。支持脚３１を係止孔１８に係止させることによって、トップカバー３をフロントケース１に固定する。トップカバー３は、このようにしてフロントケース１に固定され、煙センサ４を正面側から覆い込むと共に、凹入部１５と協働して煙センサ４に煙を誘導する環状の煙流路７を構成する。煙流路７は３６０°全ての方向に開放されており、煙は、煙流路７の外周の何れの方向からも、煙流路７に流入可能である。 On the back side of the top cover 3, as shown in FIG. 6, four support legs 31 as “support portions” arranged evenly in the circumferential direction are provided. Then, four locking holes 18 are formed at positions corresponding to the positions of the support legs 31 in the front case 1. The top cover 3 is fixed to the front case 1 by locking the support legs 31 in the locking holes 18. The top cover 3 is fixed to the front case 1 in this way, covers the smoke sensor 4 from the front side, and has an annular smoke passage 7 for guiding smoke to the smoke sensor 4 in cooperation with the recessed portion 15. Configure. The smoke channel 7 is open in all directions of 360 °, and the smoke can flow into the smoke channel 7 from any direction on the outer periphery of the smoke channel 7.

トップカバー３は、図２，図３，図７に示すごとく、正面分を正面側へ球面状に膨出して形成した中央部３２と、中央部３２の外周部分を径外方向に延長して形成された鍔部３３とを備えている。中央部３２の膨出形状の曲率半径は、「傾斜部を径内方向に延長して得られる面」としての延長面ｆ（球面形状）の曲率半径よりも大きく設定してあり、かつ、トップカバー３の正面側中心部であって、「前カバーのうち最も正面側に膨出した部分」に相当する最頂部３２ａは、延長面ｆよりも凹入部１５の側に位置する。また、中央部３２の裏面は、正面形状に対応して正面側へ膨出する形状に形成してあり、外周側から煙センサ４側に向うに従ってトップカバー３の裏面と凹入部１５の表面とが離間し、煙流路７が広がる。 As shown in FIGS. 2, 3 and 7, the top cover 3 has a central portion 32 formed by bulging the front portion in a spherical shape toward the front side, and an outer peripheral portion of the central portion 32 extending radially outward. And a flange 33 formed. The curvature radius of the bulging shape of the central portion 32 is set to be larger than the curvature radius of the extension surface f (spherical shape) as “a surface obtained by extending the inclined portion radially inward”, and the top The topmost portion 32a corresponding to the “front portion of the front cover that bulges to the most front side” is located closer to the recessed portion 15 than the extended surface f. Moreover, the back surface of the center part 32 is formed in a shape that bulges to the front side corresponding to the front shape, and the back surface of the top cover 3 and the surface of the recessed portion 15 as it goes from the outer peripheral side to the smoke sensor 4 side. Are separated, and the smoke flow path 7 is expanded.

このように、煙流路７が、外周側（入り口側）から煙センサ４に近付くに従って広がっているので、煙は、何れかの方向から煙流路７に一旦入りさえすれば、図７に示すごとく、内部の広い空間で煙センサ４の外周回りに万遍なく拡散され、煙の流れ方向にあまり影響を受けることなく、適切かつ円滑に煙導入口４１にまで到達する。 In this way, the smoke flow path 7 spreads as it approaches the smoke sensor 4 from the outer peripheral side (entrance side), so that the smoke once enters the smoke flow path 7 from any direction, as shown in FIG. As shown in the figure, the smoke is diffused uniformly around the outer periphery of the smoke sensor 4 in a wide internal space, and reaches the smoke inlet 41 appropriately and smoothly without being greatly affected by the direction of smoke flow.

鍔部３３は、図２，図３，図７に示すごとく、境界ラインｂよりも径外方向に幅ｗだけ突出させてある。鍔部３３の裏面は、径外方向に平行、または、傾斜部１６に沿う側へ少し傾斜させてある。また、鍔部３３と境界ラインｂとは、距離ｈだけ離間している。天井面Ｃから傾斜部１６に沿って流れてきた煙は、鍔部３３にぶつかって、そのまま流れ去ることがない。つまり、煙は鍔部３３に受け止められ、確実に煙流路７の内部に流入する。 As shown in FIGS. 2, 3, and 7, the flange portion 33 protrudes from the boundary line b by a width w in the radially outward direction. The back surface of the flange portion 33 is slightly inclined to the side along the inclined portion 16 in parallel to the radially outward direction. Further, the flange 33 and the boundary line b are separated by a distance h. The smoke flowing along the inclined portion 16 from the ceiling surface C hits the collar portion 33 and does not flow away as it is. That is, the smoke is received by the flange 33 and surely flows into the smoke flow path 7.

鍔部３３の突出量によって外観形状に対する印象に多少の差は出るものの、中央部３２の曲率半径を延長面ｆの曲率半径よりも大きく設定し、かつ、最頂部３２ａを延長面ｆよりも凹入部１５の側に位置させることで、少なくとも、トップカバー３の側面視における厚みが薄くなると共に、傾斜部１６とトップカバー３との連続感が演出される。よって、トップカバー３の装置全体に対する存在感が小さくなり、かつ、煙感知器全体としても薄型のものとなって、外観デザインが向上する。 Although there is a slight difference in the impression of the appearance shape depending on the protruding amount of the flange portion 33, the radius of curvature of the central portion 32 is set larger than the radius of curvature of the extended surface f, and the topmost portion 32a is recessed from the extended surface f. By being positioned on the insertion portion 15 side, at least the thickness of the top cover 3 in a side view is reduced, and a continuity between the inclined portion 16 and the top cover 3 is produced. Therefore, the presence of the top cover 3 with respect to the entire device is reduced, and the smoke detector as a whole is thin and the appearance design is improved.

ところで、支持脚３１は、トップカバー３のうち凹入部１５の範囲内に形成してあり、トップカバー３をフロントケース１に取り付けた状態では、煙流路７の奥まった箇所に位置することとなって、外観視でほとんど目立たず、外観デザインに影響を与えない。さらに、図３に示すごとく、四箇所の支持脚３１のうち少なくとも二箇所の位置は、正面視で、煙センサ４の発光部４２の近傍と、受光部４３の近傍と、になるように設定してある。つまり、支持脚３１は、そもそも煙導入口４１が設けられない発光部４２の近傍または受光部４３の近傍に位置するので、煙センサ４への煙の流入が阻害されにくい。特に図示はしないが、残りの二箇所の支持脚３１も、煙導入口４１と煙導入口４１との間の外壁面の近傍となるように配置されている。 By the way, the support leg 31 is formed in the range of the recessed portion 15 in the top cover 3, and is located in a deep part of the smoke flow path 7 when the top cover 3 is attached to the front case 1. It is hardly noticeable in appearance and does not affect the appearance design. Further, as shown in FIG. 3, at least two positions of the four support legs 31 are set to be in the vicinity of the light emitting part 42 of the smoke sensor 4 and in the vicinity of the light receiving part 43 in the front view. It is. That is, since the support leg 31 is located in the vicinity of the light emitting part 42 or the light receiving part 43 where the smoke introduction port 41 is not provided, the inflow of smoke to the smoke sensor 4 is not easily inhibited. Although not particularly illustrated, the remaining two support legs 31 are also arranged in the vicinity of the outer wall surface between the smoke inlet 41 and the smoke inlet 41.

図１乃至図３に示すごとく、フロントケース１の正面側には、ライトガイド１Ａや、音響口１３、ガス流入口１４、スイッチ１Ｂ、が備えられている。ライトガイド１Ａは、傾斜部１６に設けられた環状の発光部材であり、点灯、点滅等によって、視覚的に警報を発する。音響口１３は、スピーカ収容部１１に対応する位置において、傾斜部１６からフロントケース１の外周側部に亘ってスリット状に開口され、スピーカが発した警報音を外部に開放する。ガス流入口１４は、センサ収容部１２に対応する位置において、傾斜部１６からフロントケース１の外周面に亘ってスリット状に開口され、ＣＯガス等の流入を許容する。また、傾斜部１６とフロントケース１の外周側部とに亘る位置に、押し操作可能なスイッチ１Ｂを備えてある。スイッチ１Ｂを押すと、警報状態が解除され、スピーカ音やライドガイドの発光が止まる。 As shown in FIGS. 1 to 3, a light guide 1 </ b> A, an acoustic port 13, a gas inflow port 14, and a switch 1 </ b> B are provided on the front side of the front case 1. The light guide 1 </ b> A is an annular light emitting member provided on the inclined portion 16, and visually gives a warning when it is turned on, blinking, or the like. The sound port 13 is opened in a slit shape from the inclined portion 16 to the outer peripheral side portion of the front case 1 at a position corresponding to the speaker housing portion 11, and opens an alarm sound emitted by the speaker to the outside. The gas inlet 14 is opened in a slit shape from the inclined portion 16 to the outer peripheral surface of the front case 1 at a position corresponding to the sensor housing portion 12, and allows the inflow of CO gas or the like. In addition, a switch 1B that can be pushed is provided at a position extending between the inclined portion 16 and the outer peripheral side portion of the front case 1. When the switch 1B is pressed, the alarm state is canceled and the speaker sound and the light emission of the ride guide are stopped.

〔天井面への取り付けについて〕
煙感知器の天井面Ｃへの取り付け方法を説明する。天井面Ｃには、図２に示すごとく、予め取付ベースＳを固定してある。リアケース２の背面からは、フック形状の端子金具ｔを突出させてある。そして、端子金具ｔを取付ベースＳのうちの不図示の差し込み孔に差し込み、回転させると、端子金具ｔがその差し込み孔に係止し、煙感知器が取付ベースＳに固定される。端子金具ｔによって、取付ベースＳから、基板５に取り付けられた各部品に対して電力が供給される。 [Installation on the ceiling]
A method of attaching the smoke detector to the ceiling surface C will be described. As shown in FIG. 2, a mounting base S is fixed to the ceiling surface C in advance. A hook-shaped terminal fitting t is protruded from the rear surface of the rear case 2. When the terminal fitting t is inserted into an insertion hole (not shown) in the mounting base S and rotated, the terminal fitting t is locked in the insertion hole, and the smoke detector is fixed to the mounting base S. Electric power is supplied from the attachment base S to each component attached to the substrate 5 by the terminal fitting t.

〔煙感知性能の実証について〕
煙感知器の煙感知性能の実証実験を行ったので、図１１に基づいて以下に説明する。本発明の構成を採用したことにより煙性能が向上したことを確認すべく、本発明の構成を採用していない煙感知器についても対比実験を行った。この対比される煙感知器は、鍔部３３を有していない以外は、本発明に係る煙感知器と同じ構成を有する。詳細には、対比される煙感知器のトップカバー３には、図７に示す延長面ｆよりも径方向外側の部分（鍔部３３及び中央部３２の外周の一部）が備えられていない。 [About demonstration of smoke detection performance]
Since the demonstration experiment of the smoke detection performance of the smoke detector was conducted, the following description will be given based on FIG. In order to confirm that the smoke performance was improved by adopting the configuration of the present invention, a comparison experiment was also conducted on a smoke detector not employing the configuration of the present invention. The smoke detector to be compared has the same configuration as the smoke detector according to the present invention except that the smoke detector 33 is not provided. In detail, the top cover 3 of the smoke detector to be compared is not provided with a radially outer portion (a part of the outer periphery of the flange portion 33 and the central portion 32) than the extended surface f shown in FIG. .

本実証実験は、一定濃度の煙を一方向から他方向に直線的に流し続けている容器に、正面側を下向きにした状態で煙感知器を投入して、煙センサ４から出力を得るものであって、以下の手順で行う。
［手順１］
実証開始後１５秒後に、煙感知器を容器に投入し、センサ出力を得る。なお、センサ出力は煙濃度と対応している。
［手順２］
６０秒経過したら、煙感知器を容器から取り出し、装置内に入った煙を完全に排出させる。
［手順３］
３０秒間経過したら、煙感知器の煙の流れる方向に対する角度を４５°回転させて、再び煙感知器を容器に投入し、センサ出力を得る。 In this demonstration experiment, a smoke sensor is inserted into a container in which smoke of a constant concentration continues to flow linearly from one direction to the other, with the front side facing downward, and the output from the smoke sensor 4 is obtained. The procedure is as follows.
[Procedure 1]
After 15 seconds from the start of the demonstration, the smoke detector is put into the container and the sensor output is obtained. The sensor output corresponds to the smoke density.
[Procedure 2]
After 60 seconds, the smoke detector is removed from the container and the smoke that has entered the device is completely discharged.
[Procedure 3]
After 30 seconds, the angle of the smoke detector with respect to the direction of smoke flow is rotated by 45 °, and the smoke detector is put into the container again to obtain the sensor output.

上述の［手順１］から［手順３］９回繰り返して、全周方向（４５°毎に３６０°）からの煙に対する煙感知性能を確認した。図１１（ａ）が鍔部３３を備えていない煙感知器の実証データであり、図１１（ｂ）が本発明に係る煙感知器の実証データである。 [Procedure 1] to [Procedure 3] were repeated 9 times, and the smoke sensing performance for smoke from all directions (360 ° every 45 °) was confirmed. FIG. 11A shows demonstration data of a smoke detector that does not include the flange 33, and FIG. 11B shows demonstration data of the smoke detector according to the present invention.

図１１（ａ）から明らかなように、本発明の構成を有さない煙感知器では、うまく煙が流入せず、煙が感知できていない。本発明の構成を有さない煙感知器は、ほとんど煙を感知できなかったので、０°から１８０°までで実験を終了した。これに対して、図１１（ｂ）に示すごとく、本発明の構成を有する煙感知器であると、３６０°何れの方向からの煙であっても、即座かつ正確に感知していることが分かる。 As apparent from FIG. 11A, in the smoke detector not having the configuration of the present invention, smoke does not flow in well and smoke cannot be detected. Since the smoke detector without the configuration of the present invention could hardly detect smoke, the experiment was completed from 0 ° to 180 °. On the other hand, as shown in FIG. 11B, the smoke detector having the configuration of the present invention can immediately and accurately detect smoke from any direction of 360 °. I understand.

また、特に実証データは示さないが、本発明の構成を備えた煙感知器において、鍔部３３の幅ｗ（図７参照）、及び、境界ラインｂと鍔部３３の裏面との距離ｈ（図７参照）を、各種変更して本実証実験を行った。この実証により、幅ｗは２ｍｍ以上、距離ｈは３ｍｍ以上であると、好適な煙検知が可能であることが分かった。なお、図１１（ａ）のデータは、幅ｗが２ｍｍ、距離ｈが３．８ｍｍのものを使用している。幅ｗが２ｍｍ程度であれば、鍔部３３の突出が目立たず、煙感知器の側面視円弧形状の外観を損ねることもない。 Although no demonstration data is shown, in the smoke detector having the configuration of the present invention, the width w of the flange 33 (see FIG. 7) and the distance h between the boundary line b and the rear surface of the flange 33 ( This verification experiment was conducted with various modifications. From this demonstration, it was found that suitable smoke detection is possible when the width w is 2 mm or more and the distance h is 3 mm or more. The data in FIG. 11A uses data having a width w of 2 mm and a distance h of 3.8 mm. If the width w is about 2 mm, the protrusion of the flange 33 is not conspicuous, and the appearance of the arc shape of the smoke detector in a side view is not impaired.

〔リアケースの裏面構造について〕
煙感知器は、機器単体でも使用可能であるが、接続線Ｌによって外部機器と接続して使用することも可能である。煙感知器には、基板５に接続された出力コネクタ６を配備してある（図９，図１０参照）。外部機器と接続する場合は、接続線Ｌの一方の端部を外部機器に接続し、接続線Ｌの他方の端部に取り付けた接続コネクタＬｃを出力コネクタ６に差し込む。これにより、接続線Ｌを介して、煙センサ４やＣＯセンサ等の出力を外部機器に出力することができ、他の煙感知器と連係して外部機器による集中管理や、外部機器へのセンサ出力データの書き出し等が可能である。 [About rear case rear structure]
The smoke detector can be used as a single device, but it can also be used by connecting it to an external device via a connection line L. The smoke detector is provided with an output connector 6 connected to the substrate 5 (see FIGS. 9 and 10). When connecting to an external device, one end of the connection line L is connected to the external device, and the connection connector Lc attached to the other end of the connection line L is inserted into the output connector 6. As a result, the output of the smoke sensor 4 or the CO sensor can be output to the external device via the connection line L, and the centralized management by the external device in conjunction with other smoke detectors or the sensor to the external device Output data can be written.

しかしながら、このような天井付けの煙感知器においては、天井面Ｃにおいて発生した結露水が接続線Ｌを伝って出力コネクタ６にまで至り、機器内部の故障が誘発される虞がある。そこで、以下の構成を採用し、結露水が出力コネクタ６にまで至ることを防止している。 However, in such a smoke detector with a ceiling, the condensed water generated on the ceiling surface C reaches the output connector 6 through the connection line L, and there is a possibility that a failure inside the apparatus is induced. Therefore, the following configuration is employed to prevent the condensed water from reaching the output connector 6.

図２，図８，図９，図１０に示すごとく、リアケース２の背面部２１のうち、出力コネクタ６に対向する部分を内部側に凹入して、有底の穴である第一凹部２２を形成してある。第一凹部２２の底部２２ａの一部を開口して開口部２２ｂを設けてある。開口部２２ｂによって、出力コネクタ６の差し込み口は底部２２ａの側に向けて露出されている。出力コネクタ６を使用しないときは、図４，図６に示すごとく、第一凹部２２をコネクタカバー２Ａによって閉塞する。 As shown in FIGS. 2, 8, 9, and 10, a portion of the rear surface portion 21 of the rear case 2 facing the output connector 6 is recessed into the inner side, and a first recess that is a bottomed hole. 22 is formed. A part of the bottom 22a of the first recess 22 is opened to provide an opening 22b. The opening 22b exposes the insertion port of the output connector 6 toward the bottom 22a. When the output connector 6 is not used, the first recess 22 is closed by the connector cover 2A as shown in FIGS.

また、背面部２１のうち、周方向において第一凹部２２に隣接する部分を、内部側に凹入して第二凹部２３を形成してある。第二凹部２３は、周方向に長い有底の長穴である。さらに、背面部２１における第一凹部２２と第二凹部２３との間の部分を内部側に凹入して、第一凹部２２と第二凹部２３とを連通可能な連通凹部２４を形成してある。 Moreover, the part which adjoins the 1st recessed part 22 in the circumferential direction among the back surface parts 21 is recessed inside, and the 2nd recessed part 23 is formed. The second recess 23 is a bottomed long hole that is long in the circumferential direction. Furthermore, the part between the 1st recessed part 22 and the 2nd recessed part 23 in the back surface part 21 is recessed inside, and the communication recessed part 24 which can connect the 1st recessed part 22 and the 2nd recessed part 23 is formed. is there.

図９及び図１０に示すごとく、第一凹部２２の底部２２ａと第二凹部２３の底部２３ａとは平面状に形成してある。連通凹部２４の底部２４ａは、第一凹部２２の側から第二凹部２３の側へ向うに従って正面側に傾斜する傾斜形状に形成してある。つまり、連通凹部２４の凹入深さは、少なくとも第一凹部２２の凹入深さＤ１及び第二凹部２３の凹入深さＤ２よりも浅い。 As shown in FIGS. 9 and 10, the bottom 22 a of the first recess 22 and the bottom 23 a of the second recess 23 are formed in a planar shape. The bottom 24a of the communication recess 24 is formed in an inclined shape that inclines toward the front side from the first recess 22 side toward the second recess 23 side. That is, the recess depth of the communication recess 24 is shallower than at least the recess depth D 1 of the first recess 22 and the recess depth D 2 of the second recess 23.

そして、連通凹部２４のうち第一凹部２２の側の端部において、連通凹部２４の幅に亘ると共に、底部２４ａから背面部２１の表面にまで至る壁であるノックアウト２５をリアケース２に一体的に備えている。初期状態では、ノックアウト２５が存在するので、第一凹部２２と第二凹部２３とは連通していないが、ノックアウト２５をニッパー等の治具でリアケース２から分断すると、第一凹部２２と第二凹部２３とは連通凹部２４を介して連通する。また、連通凹部２４の底部２４ａの中間箇所に、連通凹部２４の幅に亘って背面部２１の側に突出する突起部２４ｂを備えている。 A knockout 25 that is a wall extending from the bottom 24 a to the surface of the back surface 21 is integrated with the rear case 2 at the end of the communication recess 24 on the first recess 22 side. In preparation. Since the knockout 25 exists in the initial state, the first recess 22 and the second recess 23 are not in communication with each other. However, when the knockout 25 is separated from the rear case 2 with a jig such as a nipper, the first recess 22 and the second recess 23 are not connected. The two recesses 23 communicate with each other via a communication recess 24. Further, a protrusion 24 b that protrudes toward the back surface 21 across the width of the communication recess 24 is provided at an intermediate position of the bottom 24 a of the communication recess 24.

煙感知器を外部機器と接続するときは、ノックアウト２５を分断する。そして、図１０に示すごとく、接続コネクタＬｃを出力コネクタ６に差し込む。そして、接続線Ｌの余り部分を、連通凹部２４を通して第二凹部２３に引き込み、第二凹部２３の内部にその接続線Ｌの余り部分を束ねて収納する。 When connecting the smoke detector to an external device, the knockout 25 is disconnected. Then, as shown in FIG. 10, the connection connector Lc is inserted into the output connector 6. Then, the surplus portion of the connection line L is drawn into the second recess 23 through the communication recess 24, and the surplus portion of the connection line L is bundled and stored inside the second recess 23.

このような構成とすることで、天井付近で発生した結露水が接続線Ｌを伝って垂れてきた場合は、結露水は、第一凹部２２には到達せず、第二凹部２３に溜まる。第二凹部２３の底部２３ａには、その外周に沿って溝２３ｂが掘り込んである。結露水は、溝２３ｂに接触すると、毛細管現象によって底部２３ａの全体に亘って拡散される。したがって、結露水の外気に対する接触面積が広くなって結露水の蒸発が促進され、結露水は短い時間で効率よく散逸する。 With such a configuration, when the condensed water generated near the ceiling hangs down along the connection line L, the condensed water does not reach the first concave portion 22 but accumulates in the second concave portion 23. A groove 23b is dug in the bottom 23a of the second recess 23 along the outer periphery thereof. When the condensed water comes into contact with the groove 23b, it is diffused over the entire bottom portion 23a by capillary action. Therefore, the contact area of the condensed water with the outside air is widened to promote the evaporation of the condensed water, and the condensed water is efficiently dissipated in a short time.

仮に、結露水の量が多く、第二凹部２３に結露水が溜まってしまったとしても、上述したように、連通凹部２４の凹入深さが少なくとも第二凹部２３の凹入深さＤ２よりも浅いので、結露水は連通凹部２４によって堰き止められ、第一凹部２２には侵入しない。そもそも、第二凹部２３は接続線Ｌの余り部分を収容できる程度に広く形成してあるので、結露水が連通凹部２４を乗り越えて第一凹部２２に侵入することはない。 Even if the amount of condensed water is large and the condensed water has accumulated in the second recess 23, as described above, the recess depth of the communication recess 24 is at least greater than the recess depth D2 of the second recess 23. Since it is shallow, the condensed water is blocked by the communication recess 24 and does not enter the first recess 22. In the first place, since the second recess 23 is formed wide enough to accommodate the surplus portion of the connection line L, dew condensation water does not get over the communication recess 24 and enter the first recess 22.

さらに、底部２４ａに突起部２４ｂを備えているので、図１０に示すごとく、接続線Ｌは突起部２４ｂと接触しやすい。この結果、仮に、連通凹部２４に収容された接続線Ｌを伝って第二凹部２３の側から第一凹部２２の側へ結露水が移行しようとしても、その結露水は突起部２４ｂに接触して、底部２４ａのうち突起部２４ｂよりも第二凹部２３の側へ流れ落ちる。そして、底部２４ａが傾斜形状に形成されているので、この結露水は第二凹部２３に流れ、連通凹部２４と第二凹部２３との境目の溝２３ｂ部に接触して拡散される。 Furthermore, since the protrusion 24b is provided on the bottom 24a, the connection line L is easily in contact with the protrusion 24b as shown in FIG. As a result, even if the condensed water is transferred from the second concave portion 23 side to the first concave portion 22 side through the connecting line L accommodated in the communication concave portion 24, the condensed water contacts the protruding portion 24b. Thus, the bottom 24a flows down to the second recess 23 side rather than the protrusion 24b. And since the bottom part 24a is formed in the inclined shape, this dew condensation water flows into the 2nd recessed part 23, contacts the groove | channel 23b part of the boundary of the communication recessed part 24 and the 2nd recessed part 23, and is spread | diffused.

このように、結露水を煙感知器の外部に排出することなく、迅速に散逸させられる。 In this way, the condensed water can be quickly dissipated without being discharged outside the smoke sensor.

〔別実施形態〕
（１）上述の実施形態においては、傾斜面は球面形状に形成したが、これに限られず、傾斜面は、直線状の傾斜面であっても良い。 [Another embodiment]
(1) In the above-mentioned embodiment, although the inclined surface was formed in the spherical shape, it is not restricted to this, A linear inclined surface may be sufficient as an inclined surface.

（２）上述の実施形態においては、外部から電力を供給する例を示したが、これに限られず、電池式の煙感知器であっても良い。 (2) In the above-described embodiment, an example in which power is supplied from the outside has been described. However, the present invention is not limited to this, and a battery-type smoke detector may be used.

（３）上述の実施形態においては、各部の形状を細かく定義したが、多少は形状が異なっても構わない。 (3) In the above-described embodiment, the shape of each part is finely defined, but the shape may be slightly different.

本発明は、天井設置用の複合型の煙感知器に限らず、壁設置用の煙感知器や、煙感知のみを行う煙感知器にも適用可能である。 The present invention is not limited to a composite smoke detector for ceiling installation, but can also be applied to a smoke detector for wall installation or a smoke detector that performs only smoke detection.

１フロントケース（ハウジング）
３トップカバー（前カバー）
４煙センサ
７煙流路
１５凹入部
１６傾斜部
３１支持脚（支持部）
３２ａ最頂部（前カバーのうち最も正面側に膨出した部分）
３３鍔部
４２発光部
４３受光部
ｂ境界ライン（凹入部と傾斜部との境界）
ｆ延長面（傾斜部を径内方向に延長して得られる面） 1 Front case (housing)
3 Top cover (front cover)
4 Smoke sensor 7 Smoke flow path 15 Recessed part 16 Inclined part 31 Support leg (support part)
32a Topmost part (the part of the front cover that bulges most to the front)
33 鍔 part 42 light emitting part 43 light receiving part b boundary line (boundary between the recessed part and the inclined part)
f Extension surface (surface obtained by extending the inclined part radially inward)

Claims

A smoke detector having a circular shape in front view and a substantially arc shape on the front side in side view,
It is circular when viewed from the front, and the front center part is recessed so as to approach the back side as it goes in the radially inward direction, and the front outer peripheral part adjacent to the recessed part is outside the diameter. A housing having an inclined portion formed to be inclined so as to approach the back side as it goes in the direction;
A smoke sensor supported by the housing in a state of protruding from the recessed portion to the front side;
It is circular when viewed from the front, is supported on the front side of the housing so as to face the recessed portion in a separated state, covers the smoke sensor from the front side, and cooperates with the recessed portion. A front cover that constitutes a smoke flow path for inducing smoke to the smoke sensor,
The front cover is provided with a flange portion that protrudes radially outward from the boundary between the recessed portion and the inclined portion over the entire circumference of the outer peripheral portion of the front cover,
A smoke sensor configured such that the front cover and the recessed portion are separated from the outer peripheral side toward the smoke sensor side, and the smoke flow path is widened.

The front center portion of the front cover has a shape that bulges to the front side, and the portion of the front cover that bulges to the most front side is a surface obtained by extending the inclined portion in the radial direction. The smoke detector according to claim 1, wherein the smoke detector is located closer to the recessed portion.

The smoke sensor is a photoelectric sensor having a light emitting part and a light receiving part,
The front cover is supported on the front side of the housing by a support portion provided on the front cover or the housing,
The smoke detector according to claim 1 or 2, wherein the support part is positioned in the vicinity of the light emitting part or the light receiving part in a front view.