JP7300844B2 - Smoke detectors - Google Patents

Description

TECHNICAL FIELD The present invention relates to a smoke detector having a smoke detector inside the device.

A smoke detector is generally provided with an insect net to prevent insects from entering the smoke detector. However, in a smoke sensor that has been installed for a long time, depending on the installation location, fine dust, oil, etc. may pass through the insect screen and enter the smoke detector, causing dirt to accumulate inside. If dirt such as dust, oil, and tar accumulates inside, it may cause light reflection or scattering or hinder the inflow of smoke, resulting in non-fire alarms and decreased sensitivity. In such cases, the inside of the smoke detector can be cleaned to remove dirt. However, when cleaning, it is necessary to remove and disassemble multiple parts of the smoke detector in high places such as ceilings, clean each part, reassemble and reinstall, which takes time. was In order to solve this problem, a method was devised in which dust inside the smoke sensor is removed by vacuuming, without removing most of the smoke sensor parts.

Japanese Patent Application No. 2017-175503

Patent Literature 1 describes a smoke sensor that can remove dust inside by providing holes for suction on the outer surface. However, although the smoke sensor of Patent Document 1 can remove dust such as dust and sand that have entered inside, it is difficult to remove sticky stains such as oil stains and cigarette tar. An object of the present invention is to provide a smoke sensor that can maintain performance without incurring costs such as replacement of parts while simplifying the removal of parts for cleaning and reducing the burden on cleaning workers.

The present invention is intended to solve the above problems, and has the following configurations.

(1) The present invention includes an optical bench housing a light emitting element and a light receiving element, a back plate on which the optical bench is mounted, an optical bench cover covering the optical bench, and a cover main body covering the optical bench cover. and wherein the optical bench cover is removed from the optical bench together with the cover body when the cover body is removed from the back plate.

(2) Further, in the present invention, the cover main body includes an inclined portion having an opening, a plurality of pillars having one end connected to the opening side of the inclined portion and erected, and a plurality of the pillars. a protective plate connected to the other end of the optical bench cover; and a smoke inlet portion surrounded by the opening, the strut, and the protective plate. The smoke sensor according to (1), characterized in that it is detachably fixed.

(3) Further, the present invention is the smoke sensor according to (1), wherein the optical bench cover is detachably fixed to the cover body by adhesive.

(4) Further, the present invention includes an optical table housing a light emitting element and a light receiving element, a back plate on which the optical table is mounted, a first optical table cover covering the optical table, and the first optical table. a second optical bench cover that covers the optical bench cover; and a cover main body that covers the second optical bench cover. When the cover body is removed from the back plate, the second optical bench cover is removed from the optical bench integrally with the cover body while the first optical bench cover is attached to the optical bench. A smoke detector characterized by

(5) Further, according to the present invention, the cover main body has a locking column inside, the second optical bench cover has a protruding plate on the side, and the locking piece of the locking column protrudes. The smoke sensor according to (4), characterized in that the plate is locked.

(6) Further, according to the present invention, a substrate on which the light-emitting element and the light-receiving element are installed is provided between the back plate and the optical bench, the optical bench cover has a flange on its circumference, and the flange is detachably fixed to the cover body by fitting inside the support column.
(7) Further, according to the present invention, a concave portion is provided on the outer periphery of the flange, and the inner side of the support is fitted into the concave portion to fix the optical bench cover to the cover main body. The smoke detector described.

According to the present invention, dirt on the optical table and the optical table cover can be directly cleaned simply by removing the cover body that covers the lower part of the smoke sensor. Preventing smoke detector can be realized.

1 is an exploded view of a photoelectric spot type smoke sensor 1 in Example 1 of the present invention. FIG. FIG. 2 is an exploded view of the smoke sensor 1 into a fixing portion 3 and a cover portion 2 in Embodiment 1 of the present invention. FIG. 4 is a cut end view showing an end face near the smoke inflow part 45 of the cover part 2 in Embodiment 1 of the present invention. FIG. 4 is a cut end view showing an end face of the cover part 2 in the vicinity of the pillars 44 in the first embodiment of the present invention; Sectional drawing in the flange 52 part of the cover part 2 in Example 1 of this invention. FIG. 2 is an exploded view of a photoelectric spot type smoke sensor according to a second embodiment of the present invention; The figure which decomposed|disassembled the smoke sensor in Example 2 of this invention into a fixing|fixed part and a cover part. FIG. 10 is an oblique projection view of the upper surface of the cover portion in Embodiment 2 of the present invention. FIG. 11 is an enlarged view of a locking column portion of the top view of the cover portion in Embodiment 2 of the present invention; FIG. 10 is an end view of the cover part in Example 2 of the present invention, taken along line DD in FIG. 9; FIG. 4 is a vertically cut end view of the smoke sensor in Example 2 of the present invention; FIG. 3 is a bottom view of the first optical bench cover in Embodiment 2 of the present invention; FIG. 10 is a top view of a second optical bench cover in Embodiment 2 of the present invention;

EMBODIMENT OF THE INVENTION Below, the form for implementing invention of this application is described. The vertical direction indicates the vertical direction when the smoke sensor is installed on a horizontal ceiling. The same is true for the horizontal and vertical directions.

FIG. 1 is an exploded view of a photoelectric spot type smoke sensor 1 according to a first embodiment of the present invention. The smoke sensor 1 of Example 1 is composed of a cover body 4, an optical bench cover 5, an optical bench 6, a substrate 7, and a back plate 8. The cover body 4 and the optical bench cover 5 cover the cover part 2, 6 , the substrate 7 and the back plate 8 constitute the fixed part 3 . The optical bench 6, the optical bench cover 5, and the substrate 7 having the light-emitting element 71, the light-receiving element 72, and the circuit constitute a smoke detector.

A cover body 4 of the smoke sensor 1 covers and protects internal parts of the smoke sensor 1 attached to a ceiling or the like from below. The inclined portion 41 of the cover main body 4 covers the internal parts with the peripheral portion of the lower surface of the cover main body 4, and has a gently inclined conical shape. A circular opening 42 is provided in the central portion of the inclined portion 41, and a smoke detection device is fitted therein. The protective plate 43 of the cover body 4 is located at the lowest part of the smoke sensor 1 and covers and protects the lower part of the smoke detector.

The cover main body 4 has six struts 44 surrounding the opening 42 at regular intervals. The post 44 is erected with one end connected to the inclined portion 41 near the opening 42 . The other end of the strut 44 is connected to the protective plate 43 , and the six struts 44 support the protective plate 43 . The smoke inflow portion 45 is an opening surrounded by the end portion of the opening portion 42 in the inclined portion 41 , the strut 44 and the protective plate 43 . Six smoke inflow portions 45 are provided along the periphery of the opening 42 of the cover body 4, and smoke flows into the smoke detection portion in the smoke detection device when smoke is generated. A confirmation lamp window 46 is a hole formed in the inclined portion 41 to expose the confirmation lamp 73 from the cover main body 4 . Two confirmation lamp windows 46 are provided in accordance with the number of confirmation lamps 73, but the number of confirmation lamps 73 and confirmation lamp window 46 may be one instead of two.

An optical bench cover 5 of the smoke sensor 1 is provided between the cover body 4 and the optical bench 6 to cover the optical bench 6 from below and from the sides. The optical bench cover 5 has six optical bench cover supports 54 erected around an optical bench cover bottom portion 53 below, and an insect screen 55 is provided between the optical bench cover supports 54 . A ring-shaped peripheral portion 51 is provided on the upper portion of the insect screen 55 . The peripheral portion 51 , the optical bench cover struts 54 , and the insect screen 55 surround the optical bench 6 when the optical bench cover 5 covers the optical bench 6 . The peripheral portion 51 has no structure for directly fixing to the optical bench 6 , and the optical bench cover 5 is not directly fixed to the optical bench 6 . It should be noted that the peripheral portion 51 of the optical bench cover 5 may be short in the vertical direction, and may not completely cover the periphery of the upper portion of the optical bench 6 .

The flange 52 is a part of the peripheral portion 51 , is provided on the outer periphery of the upper portion of the insect screen 55 , and protrudes in the outer peripheral direction of the optical bench cover 5 at the lower end of the peripheral portion 51 . Further, the flange 52 closes the gap inside the opening 42 in the cover body 4 to prevent foreign matter from entering the inside of the smoke sensor 1 due to mischief or the like. The flange 52 is provided with a flange recess 521 for fixing the optical bench cover 5 to the cover main body 4 . The flange recesses 521 are fitted to the supports 44 of the cover body 4 .

The optical bench cover 5 is made of black resin that absorbs light, and the optical bench cover bottom portion 53 prevents external light from penetrating from below and entering the smoke detector. The optical bench cover struts 54 are located below the flange recess 521 and are located inside the six struts 44 of the cover body 4 in a state where the optical bench cover 5 is attached to the cover body 4 . When the optical bench cover 5 is assembled to the cover main body 4, the insect screen 55 is positioned inside the smoke inflow portion 45 of the cover main body 4 to prevent entry of insects, dust, dust, etc. into the smoke detector.

It should be noted that the plurality of support columns 44 and optical bench cover support columns 54 may be more or less than six as long as they stably support the protection plate 43 and the optical bench cover bottom portion 53 and do not block the inflow of smoke. It may be a book, seven books, or the like. Also, although the columns 44 and the optical bench cover columns 54 are arranged around the opening 42 at regular intervals, they may not be arranged at regular intervals. The same applies to the smoke inflow portion 45 sandwiched between adjacent struts 44 .

The optical bench 6 has a labyrinth wall 61 and a top wall 62 shown in FIG. are doing. The optical bench 6 is also made of black resin that absorbs light. The smoke detector inside the labyrinth wall 61 is covered with the labyrinth wall 61 and the top wall 62 as well as the optical bench cover bottom portion 53 of the optical bench cover 5, thereby preventing external light from entering.

The light-emitting element cover 63 accommodates the light-emitting element 71 installed on the substrate 7 , and the light-receiving element cover 64 accommodates the light-receiving element 72 installed on the substrate 7 . The light-emitting element cover 63 and the light-receiving element cover 64 cover the light-emitting element 71 and the light-receiving element 72 except for the light-emitting direction and the light-receiving direction. The optical axes of the light emitting direction and the light receiving direction are shifted by 60°, and a labyrinth wall 61 is provided between the light emitting element 71 and the light receiving element 72 . Therefore, the light from the light emitting element 71 does not reach the light receiving element 72 directly, and only the scattered light reaches it. In addition, the light-emitting element cover 63 and the light-receiving element cover 64 prevent dust from adhering to the light-emitting element 71 and the light-receiving element 72, and prevent cleaning tools from contacting the light-emitting element 71 and the light-receiving element 72 during cleaning. The light emitting element 71 and the light receiving element 72 are protected and prevented from being misaligned.

The substrate 7 is provided with a light-emitting element 71, a light-receiving element 72, a circuit for detecting smoke, a circuit for communicating with a receiver, and a confirmation light 73. The confirmation light 73 lights up when smoke is detected to indicate the operating state. The light-emitting element 71 is composed of an LED and always emits light intermittently, and the light-receiving element 72 is composed of a photodiode and receives incident light and converts it into an electric signal. The board fixing screw 74 fixes the board 7 to the back plate 8 and also fixes the ceiling mounting bracket 81 . Also, the optical bench 6 is inserted into and fixed to the substrate 7 .

The fixing portion 3 composed of the optical bench 6, the substrate 7, and the back plate 8 is attached to a fixture (not shown) provided on the ceiling with a ceiling mounting bracket 81. As shown in FIG. Also, the cover body 4 of the cover portion 2 is attached to the back plate 8 through a snap-fit connection port 82 .

FIG. 2 is a diagram of the smoke sensor 1 separated into a fixed part 3 and a cover part 2 in the first embodiment. When cleaning the inside of the smoke detector, it is separated into the state shown in FIG. 2 and wiped off. In the smoke sensor 1 of the first embodiment, the cover part 2 having the optical bench cover 5 attached to the cover main body 4 is snapped onto the fixed part 3 having the optical bench 6 fixed to the substrate 7 and the substrate 7 fixed to the back plate 8 . It is assembled by being detachably attached by a fit connection port 82. - 特許庁

The cover portion 2 consisting of the cover body 4 and the optical bench cover 5 is lightly attached by fitting the flange 52 of the peripheral portion 51 of the optical bench cover 5 into the opening 42 of the cover body 4 . When the cover part 2 is removed from the fixed part 3, the inside of the optical bench cover 5 is exposed and can be cleaned. In addition, the fixed portion 3 composed of the optical bench 6, the substrate 7, and the back plate 8 exposes the labyrinth wall 61, the light emitting element cover 63, the light receiving element cover 64, and the upper surface wall 62 of the optical table 6 so that they can be cleaned.

When cleaning, only the cover part 2 needs to be removed from the installed smoke sensor 1, and the cover main body 4 and the optical bench cover 5 do not have to be removed separately, which facilitates the work. When cleaning is performed by a cleaning worker who has climbed a stepladder or the like, since there is no place to place the optical bench cover 5, etc., if they are removed separately, the cover main body 4 and the optical bench cover 5 must be held individually. I have to work while Although the optical bench cover 5 and the like can be placed on a stand, floor, or the like, in that case, they must be moved by, for example, getting off the stepladder. However, in Embodiment 1 of the present invention, the cleaning operator only needs to hold the cover part 2. Therefore, the operator holds the cover body 4 of the cover part 2 with one hand and the cleaning tool such as cloth with the other hand. can be held and cleaned easily. After cleaning, the cover part 2 can be reattached to the fixed part 3 to monitor smoke from the fire.

The smoke sensor 1 can be removed from the ceiling or the like with the fixed part 3 attached to the ceiling, and the cover main body 4 to which the optical bench cover 5 is fitted and attached as shown in FIG. Further, when the cleaning worker removes the cover body 4 from the installed smoke sensor 1, the optical bench cover 5 does not drop from the cover body 4. - 特許庁For cleaning the inside, the smoke sensor 1 is removed from the ceiling and turned upside down. However, since the optical bench cover 5 does not fall off the cover body 4, the work is easy.

Next, the engagement between the cover main body 4 and the optical bench cover 5 will be described using the cross-sectional structure of the cover portion 2 shown in the lower portion of FIG. FIG. 3 is a cross-sectional end view showing an end face near the smoke inflow portion 45 of the cover portion 2 in Embodiment 1 of the present invention. FIG. 3(a) is a bottom view of the cover portion 2 showing the cutting position on the drawing, FIG. 3(b) is an end view of the cut portion of the cover portion 2 taken along line AA, and FIG. It is an enlarged view of the smoke inflow part 45 part of b).

As shown in FIG. 3A, which is a bottom view, only the cover main body 4 can be seen when the cover portion 2 is viewed from below. A protective plate 43 is provided in the center of the cover body 4 , and pillars 44 are provided at six locations around the protective plate 43 at equal intervals.

FIG. 3(b) is a view of the cover portion 2 cut along line AA where the smoke inlet 45 and the confirmation light window 46 are located in FIG. 3(a). The optical bench cover 5 is attached to the cover main body 4 from above, and is fitted and fixed inside the opening 42 of the cover main body 4 . An insect screen 55 of the optical bench cover 5 is positioned just inside the smoke inlet 45 of the cover main body 4 .

FIG.3(c) is an enlarged view of the lower left part of the smoke inflow part 45 in FIG.3(b). A protection plate 43 of the cover main body 4 extends downward, and an inclined portion 41 extends from the opening 42 in the upper left. A smoke inflow portion 45 is formed by opening between the inclined portion 41 and the protection plate 43 . An optical bench cover bottom portion 53 of the optical bench cover 5 is placed on the protective plate 43 of the cover body 4 , and an insect screen 55 of the optical bench cover 5 is placed inside the smoke inlet 45 of the cover body 4 . The flange 52 of the peripheral portion 51 of the optical bench cover 5 is positioned inside the opening 42 .

As shown in the end view of FIG. 3(c), the peripheral portion 51 has a flange 52 extending leftward. The peripheral portion 51 has a cylindrical shape and surrounds the upper periphery of the optical bench 6 placed on the fixed portion 3 when the cover portion 2 is attached to the fixed portion 3 . A flange 52 at the lower end of the peripheral portion 51 protrudes from the peripheral portion in a ring shape.

The insect screen 55 is formed of a metal mesh in a cylindrical shape and is provided inside the smoke inlet portion 45 of the cover body 4 . In addition, non-fire alarms are prevented by preventing insects, large pieces of dust, dust, etc. from entering the smoke detecting device. On the other hand, the insect screen 55 does not block the fire smoke reaching around the sensor and allows it to flow into the smoke detector. In the smoke sensor 1 in which the cover part 2 is attached to the fixed part 3, in FIG. Enter the inside of the broken smoke detector. Fine particles such as fine dust and oily smoke enter the inside of the smoke detector from the left side. Since fine particles such as fine dust and oil stains that have entered adhere to the optical bench cover bottom portion 53 and the optical bench 6, they are removed by cleaning. In addition, if the installation period of the sensor is long, dust and the like may adhere to the inside and outside of the insect screen 55, making it difficult for smoke to flow in. Dust and the like can be removed.

FIG. 4 is a cross-sectional end view showing an end face of the cover part 2 near the strut 44 in the first embodiment of the present invention. FIG. 4(a) is a cut end view of the cover portion 2 taken along the line BB, and FIG. 4(b) is an enlarged view of the column 44 portion of FIG. 4(a).

FIG. 4(a) is a bottom view of FIG. 3(a) showing the cover 2 cut along the line BB where the post 44 is located. The attached cut end is shown. In the end view of FIG. 4( a ), cut surfaces of the snap fit 47 are shown on the upper left and right sides of the cover body 4 . The cover part 2 is attached to the fixed part 3 by connecting the snap fit 47 to the snap fit connection port 82 of the back plate 8 shown in FIG. Also, during cleaning, a rod-shaped body is inserted through the lower hole to push the snap-fit connection port 82 outward. By removing the snap fit 47 from the snap fit connection port 82 and pulling out the cover part 2 downward, the cover main body 4 and the optical bench cover 5 constituting the cover part 2 can be removed integrally. It should be noted that the snap fit 47 may be removed by pushing it inward with a rod-shaped body.

FIG. 4(b) is an enlarged view of the pillar 44 portion located at the lower left of FIG. 4(a). FIG. 4(b) is an end view of a cut portion, but shows the flange 52 behind for explanation, and the side surface of the flange recess 521 is shown behind the post inner protrusion 441. FIG. A protection plate 43 of the cover main body 4 is provided at the bottom of the drawing, and an inclined portion 41 of the cover main body 4 is provided on both sides of the column 44 on the left side. An optical bench cover bottom portion 53 of the optical bench cover 5 is positioned on the protective plate 43 of the cover body 4 , and an optical bench cover support post 54 and a peripheral portion 51 of the optical bench cover 5 are positioned inside the support posts 44 of the cover body 4 . .

The peripheral portion 51 is not directly attached to the optical bench 6 while the cover portion 2 is attached to the fixed portion 3 . Therefore, when the snap fit 47 of the cover main body 4 is removed and the cover portion 2 is removed from the fixed portion 3, the peripheral edge portion 51 of the optical bench cover 5 is easily separated from the optical bench 6, and the optical bench cover 5 is closed. It remains on the body 4 side. A conventional smoke detector uses a smoke detection device in which portions corresponding to the peripheral portion 51 and the optical bench 6 of the first embodiment of the present invention are directly fixed or attached. However, in the first embodiment of the present invention, since the peripheral portion 51 is not directly attached to the fixing portion 3 such as the optical bench 6, the optical bench cover 5 can be cleaned without removing the optical bench cover 5 from the optical bench 6. 4, the optical bench cover 5 is removed.

In the cover body 4 , the strut 44 protrudes inward from the opening 42 and forms a strut inner protrusion 441 . Also, in the optical bench cover 5 , the flange 52 is notched in accordance with the post inner protrusion 441 to form a flange recess 521 . In the cover portion 2 , the column inner convex portion 441 of each column 44 is fitted into the flange concave portion 521 to fix the optical bench cover 5 . By fitting, the side surface of the flange concave portion 521 shown in FIG. 4(b) sandwiches the side surface of the post inner convex portion 441, and is fixed by friction.

By using the column inner protrusion 441 in this manner, the optical bench cover 5 can be attached to the cover main body 4 without providing any other special configuration. Furthermore, since the position of the optical bench cover 5 in the rotational direction is defined by the flange recess 521, the optical bench cover support 54 is positioned inside the support 44 and is not displaced to a position that prevents the inflow of smoke from the smoke inlet 45. There is no

The optical bench cover 5 is lightly fixed to the inner side of the cover body 4 at the portion of the support 44 . Therefore, by pinching the peripheral edge portion 51 and pulling out the optical bench cover 5 from the opening 42 of the cover main body 4, the flange concave portion 521 is removed from the column inner convex portion 441, and the cover main body 4 and the optical bench cover 5 are easily separated. be able to.

FIG. 5 is a cross-sectional view of the flange 52 portion of the cover portion 2 in Example 1 of the present invention. FIG. 5(a) is a side view of the cover portion 2 showing the cutting position on the drawing, FIG. 5(b) is a cross-sectional view of the cover portion 2 taken along line CC, and FIG. 5(c) is FIG. 5(b). 1 is an enlarged view of a support 44 portion of FIG.

FIG. 5(a) is a side view of the cover portion 2, and the optical bench cover 5 is attached to the cover main body 4 as in FIG. 3(a). When the cover portion 2 is viewed from the side, the outside of the insect screen 55 of the optical bench cover 5 is exposed behind the smoke inlet portion 45 of the cover main body 4 sandwiched between the posts 44 . FIG. 5(a) is a diagram showing the position of the CC line, which is the cutting line of the cross-sectional view of FIG. 5(b). It is a horizontal plane that cuts the struts 44 together.

FIG. 5(b) is a view of the cover portion 2 cut along the line CC where the flange 52 and the strut 44 are located. A central portion of the cover portion 2 is open, and an optical bench 6 is positioned when the cover portion 2 is attached to the fixed portion 3 . FIG. 5B shows how the cylindrical optical bench cover 5 is fitted inside the inclined portion 41 of the cover body 4 . Of the cross sections in the figure, the inner section is the section of the flange 52 portion of the optical bench cover 5, and the outer section is the section directly above the opening 42 of the cover body 4, which is the section of the support 44 and the inclined portion 41. ing.

FIG. 5(c) is an enlarged view of the strut 44 portion of FIG. 5(b). As shown in FIG. 5(c), the post inner protrusion 441 is fitted into the flange recess 521. As shown in FIG. In the smoke sensor 1 according to the first embodiment, the support inner projections 441 of the respective supports 44 are fitted into the flange recesses 521, so that the cover main body 4 and the optical bench cover 5 are combined and integrated. Further, when fitting, the two side surfaces of the flange concave portion 521 sandwich and contact the two side surfaces of the post inner convex portion 441 , whereby the optical bench cover 5 is attached to the cover main body 4 . The fitting between the flange concave portion 521 and the column inner convex portion 441 may be performed by friction due to contact between the bottom of the concave portion and the peak of the convex portion instead of sandwiching by the side surface, or the outer peripheral surface of the flange 52 and the opening of the inclined portion 41. It may be due to friction due to contact with the inner peripheral surface of the portion 42 .

Since the optical bench cover 5 is only lightly fixed by fitting with the cover main body 4, it can be freely attached and detached when it is desired to separate the optical bench cover 5 from the cover main body 4 for cleaning when it is heavily soiled. be. Further, at this time, since the contact portion between the cover main body 4 and the optical bench cover 5 is small in the engagement between the post inner convex portion 441 and the flange concave portion 521, the cover body 4 and the optical bench cover 5 are easily pulled out. Further, as shown in the figure, the presence of the flange 52 closes the gap between the cover body 4 and the optical bench cover 5 . Therefore, it is possible to prevent the board 7 from being damaged by a wire being inserted by mischief or the like, and the intrusion of foreign matter.

According to the first embodiment of the present invention, when cleaning the inside of the optical bench 6, the cover main body 4 and the optical bench cover 5 can be removed together as the cover part 2, exposing the inside of the smoke detector. Removes dust, oil stains, etc. At this time, only the cover main body 4 is required to be removed or gripped by the cleaning operator, which facilitates cleaning. Further, since the cover body 4 and the optical bench cover 5 are integrated, the cover body 4 and the optical bench cover 5 can be attached at once after removing and cleaning. When cleaning, if the cover part 2 is removed while the fixed part 3 is attached to the ceiling, the inside of the optical table 6 and the optical table cover 5 should be cleaned with a cloth or a cotton swab while holding the cover part 2 with one hand. can do. Further, even if the cover main body 4 is held with the side of the optical bench cover 5 facing downward during cleaning, the optical bench cover 5 does not fall off, making the work easier. When removing the cover 2 after removing the smoke sensor from the ceiling or the like, the smoke sensor 1 must be turned upside down before removal. At this time, the optical bench cover 5 positioned below does not drop from the cover main body 4. - 特許庁Since the support pillars 44 supporting the protective plate 43 are used to connect the optical bench cover 5 and the cover main body 4, they can be detachably attached with a simple structure without providing other structures. Further, since positioning is performed by the post inner convex portion 441 and the flange concave portion 521, the positions of the optical bench cover 5 and the cover main body 4 in the rotational direction are determined. Therefore, the optical bench cover post 54 is positioned inside the post 44 and does not block the inflow of smoke. Moreover, since the gap between the optical bench cover 5 and the cover main body 4 is covered with the flange 52, it is possible to prevent a member such as a wire from being inserted from the opening 42 toward the substrate 7 by mischief or the like.

<Modification of Embodiment 1>
The flange 52 provided on the peripheral portion 51 of the optical bench cover 5 in the first embodiment may be omitted. In this case, the optical bench cover 5 can be detachably fixed by fitting the peripheral edge portion 51 to the inside of each support 44 and the inner peripheral surface of the opening 42 of the inclined portion 41 . Further, although the labyrinth wall 61 is provided on the optical bench 6 in the smoke sensor 1 of the first embodiment, part or all of the labyrinth wall 61 may be provided on the optical bench cover 5 side. A two-layer structure of a labyrinth and a smoke detector as in Patent Document 1 may also be used.

Also, a method using double-sided tape may be used to connect the optical bench cover and the cover main body. Also in this case, the optical bench cover can be detachably fixed to the cover body with a simple configuration. Using this method, the connection part to the optical bench, etc., is removed from the optical bench cover of the conventional smoke sensor that has already been manufactured, and the optical bench cover bottom, etc. is fixed to the back of the protective plate of the cover body with double-sided tape. Thus, the smoke sensor of the first embodiment of the present invention having a detachable cover can be easily modified.

In addition, in the first embodiment, the cover body has an inclined portion with an opening, and a protective plate is provided via a plurality of pillars provided around the opening. Although described in terms of sensors, the present invention is not limited to this and can be applied to various sensors.
For example, the smoke inlet may be provided on the side surface of the cover body, and may be applied to a thin sensor in which the smoke inlet does not protrude downward.

FIG. 6 is an exploded view of a photoelectric spot type smoke sensor 11 according to a second embodiment of the present invention. The smoke sensor 11 of the second embodiment includes a cover main body 14, a second optical bench cover 15, a first optical bench cover 19, an optical bench 16, and an optical bench extending portion integrally extending in the horizontal direction of the optical bench 16. The cover main body 14 and the second optical bench cover 15 constitute the cover portion 12, the first optical bench cover 19, the optical bench 16, the optical bench extension portion 17, and the back plate 18 constitute the fixed portion. 13. A light-emitting element, a light-receiving element, and a circuit board are provided above the optical bench 16 and the optical bench extension portion 17, and the optical bench 16, the first optical bench cover 19, the second optical bench cover 15, and the optical bench extension The part 17, the light-emitting element, the light-receiving element, and the circuit board constitute a smoke detector. The labyrinth space inside the smoke detector is divided into upper and lower layers by the first optical bench cover 19 . Although the optical bench 16 is not directly visible in FIG. 6, it is provided on top of the first optical bench cover 19, and includes a substantially cylindrical wall, a substantially disk portion connected thereon, a light emitting element and a light receiving element. It is formed by openings for, labyrinth walls or the like. The upper labyrinth formed by the optical bench 16 and the first optical bench cover 19 serves as a smoke detector 165, and the lower labyrinth formed by the first optical bench cover 19 and the second optical bench cover 15 serves as a light shielding and guiding part. Has a smoke role. When the cover portion 12 is removed from the fixed portion 13, the inside of the lower labyrinth is exposed.

A cover body 14 of the smoke sensor 11 covers and protects internal parts of the smoke sensor 11 attached to a ceiling or the like from below. The inclined portion 141 of the cover main body 14 covers the internal parts with the peripheral portion of the lower surface of the cover main body 14, and has a gently inclined conical shape. A circular opening 142 is formed in the central portion of the inclined portion 141, and the second optical bench cover 15 is fitted therein. The protective plate 143 of the cover body 14 is located at the lowest part of the smoke sensor 11 and covers and protects the lower part of the second optical bench cover 15 .

The cover body 14 has six struts 144 surrounding the opening 142 at regular intervals. The post 144 is erected with one end connected to the inclined portion 141 near the opening 142 . The other end of the strut 144 is connected to the protective plate 143, and the six struts 144 support the protective plate 143. As shown in FIG. The smoke inflow portion 145 is an opening surrounded by the end portion of the opening portion 142 in the inclined portion 141 , the strut 144 and the protective plate 143 . Six smoke inflow portions 145 are provided along the periphery of the opening 142 of the cover body 14, and smoke flows into the smoke detector when smoke is generated. The confirmation lamp window 146 is a window provided in the inclined portion 141 so that the light of the confirmation lamp 173 provided on the circuit board can be visually recognized from the lower part of the cover main body 14, and is fitted with a transparent resin member. Two confirmation lamp windows 146 are provided in accordance with the number of confirmation lamps 173, but the number of confirmation lamps 173 and confirmation lamp window 146 may be one instead of two.

The second optical bench cover 15 of the smoke sensor 11 is provided between the cover body 14 and the first optical bench cover 19 to cover the inside of the smoke detector from below and from the sides. The second optical bench cover 15 is made of black resin that absorbs light. The second optical bench cover 15 has six optical bench cover support posts 154 erected around a second cover bottom portion 153 below, and a ring-shaped peripheral edge portion 151 is provided on the top of the optical bench cover support posts 154 . . An insect screen 155 is provided inside the peripheral edge 151 and the optical bench cover column 154 . A smoke inlet 159, which is an opening, is formed by the peripheral edge portion 151, the optical bench cover column 154, and the outer peripheral portion of the second cover bottom portion 153. FIG. The peripheral portion 151, the optical bench cover post 154, the insect screen 155, and the smoke inlet 159 surround the smoke detector when the second optical bench cover 15 covers the lower part of the smoke detector. It should be noted that the second optical bench cover 15 does not have a structure for directly fixing to the structure of the fixing portion 13 .

The flange 152 is a part of the peripheral portion 151 and protrudes in the outer peripheral direction of the second optical bench cover 15 at the upper end of the peripheral portion 151 . In addition, the flange 152 closes the gap above the opening 142 when the second optical bench cover 15 is attached to the cover main body 14, preventing entry of dust and foreign matter into the smoke sensor 11 due to mischief. prevent. A projecting plate 156 is provided on the flange 152 to fix the second optical bench cover 15 to the cover main body 14 . The protruding plate 156 extends further upward from a part of the outer peripheral end of the flange 152 and protrudes outward in a plate shape. A protruding plate 156 is provided on each side of the second optical bench cover 15, and the protruding plate 156 is provided with a protruding plate notch 156a.

A disk-shaped second cover bottom portion 153 provided on the bottom surface of the second optical bench cover 15 is low in the central portion and the outer peripheral portion, and high in the intermediate portion. The annular concave portion 158b is on the lower surface side of this intermediate portion, and the annular convex portion 158a in FIG. 8, which will be described later, is on the upper surface side of this intermediate portion. The annular concave portion 158b and the annular convex portion 158a surround the central portion of the second cover bottom portion 153 in a circular shape. The second cover bottom portion 153 prevents external light from penetrating from below and entering the smoke detecting device, and prevents external light entering the inside of the smoke detecting device from the side by forming an annular concave-convex structure with annular convex portions 158a and the like. blocked by

The insect screen 155 is formed by forming a metallic mesh into a cylindrical shape, and is provided inside the optical bench cover column 154 and the smoke inlet 159 in the second optical bench cover 15 . When the smoke detector 11 is installed, the insect screen 155 is positioned inside the smoke inlet portion 145 of the cover body 14 to prevent insects, large dust particles, sand dust, etc. from entering the smoke detection device. Prevents fire alarms. On the other hand, the insect screen 155 does not block the fire smoke reaching around the sensor and allows it to flow into the smoke detector. When the second optical bench cover 15 is assembled to the cover main body 14, the smoke inlet 159 is positioned inside the smoke inlet 145 of the cover main body 14, and the insect screen 155 covers all the smoke inlets 159 from the inside. ing. The optical bench cover struts 154 are located inside the six struts 144 of the cover body 14 in a state where the second optical bench cover 15 is attached to the cover body 14 . It should be noted that the plurality of support columns 144 and optical bench cover support columns 154 may be more or less than six as long as they stably support the protection plate 143 and the second cover bottom portion 153 and do not block the inflow of smoke. It may be a book, seven books, or the like. Also, although the columns 144 and the optical bench cover columns 154 are arranged around the opening 142 at regular intervals, they may not be arranged at regular intervals. The same applies to the smoke inflow portion 145 and the smoke inflow port 159 sandwiched between adjacent struts 144 .

A first optical bench cover 19 of the smoke sensor 11 is provided between the second optical bench cover 15 and the optical bench 16 to cover the optical bench 16 from below and from the sides. Like the second optical bench cover 15, the first optical bench cover 19 is made of black resin that absorbs light. In the first optical bench cover 19, six plate-like smoke introducing fins 194 radially hang down from the lower surface of a disk-like first cover disk 191 having a cover central opening 193 at the center. The first cover disc 191 has a thick portion 192 around the cover central opening 193 , and the thick portion 192 becomes thicker so that the lower surface side gradually decreases as it approaches the cover central opening 193 . The lower end of the smoke introduction fin 194 is cut out in a concave shape substantially matching the inclination of the second cover bottom portion 153 . When the first optical bench cover 19 and the second optical bench cover 15 are put together, the smoke introduction fins 194 are located inside the optical bench cover support 154 and continue to the position of the cover central opening 193 as a labyrinth wall. The cover central opening 193 connects the upper and lower labyrinth spaces of the smoke detector, and the smoke entering the smoke inlet 159 from the smoke inlet 145 reaches the upper smoke detector 165 through the cover central opening 193 .

The optical bench 16 is integrally provided in the center of the optical bench extension portion 17 and the bottom surface thereof is covered with a first optical bench cover 19 . The optical bench 16 has a labyrinth wall, a peripheral wall, and a top wall to prevent outside light from entering the smoke detector 165 from the side and top and to prevent the light from the light emitting element from reaching the light receiving element directly. (not shown). The optical bench 16 is also made of black resin that absorbs light, like the first optical bench cover 19 and the like. 11, which will be described later, is covered by the first cover disk 191 of the first optical bench cover 19 in addition to the peripheral wall and top wall of the optical bench 16, and only the cover central opening 193 is open. . In the central opening 193 of the cover, outside light is prevented from entering by the smoke introducing fins 194 and the second cover bottom portion 153 of the second optical bench cover 15 .

The circuit board is provided with a circuit for detecting smoke, a circuit (not shown) for communication with the receiver, and a confirmation light 173. The light emitting element and the light receiving element are connected via the optical bench 16. ing. The confirmation light 173 lights up when smoke is detected to indicate the operating state. The light-emitting element is composed of an LED and always emits light intermittently, and the light-receiving element is composed of a photodiode and receives incident scattered light and converts it into an electric signal. The board fixing screw 174 fixes the optical bench extension 17 to the back plate 18 , and the ceiling mounting bracket 181 is also fixed to the back plate 18 . The optical bench 16 is integral with and fixed to the optical bench extension portion 17 .

The fixing portion 13, in which the optical bench extension portion 17, the optical bench 16, and the first optical bench cover 19 are fixed to the back plate 18, is attached to a fixture (not shown) provided on the ceiling by a ceiling mounting bracket 181. FIG. Further, the body fixing screw 183 is passed through the screw hole 182 of the back plate 18 to fix the cover body 14 of the cover part 12 , whereby the cover part 12 is attached to the fixed part 13 .

FIG. 7 is an exploded view of the smoke sensor 11 according to Embodiment 2 of the present invention into a fixing portion 13 and a cover portion 12. As shown in FIG. When cleaning the inside of the smoke detector, it is separated into the states shown in FIG. The fixed portion 13 in the state of FIG. 7 is in a state where the optical bench extension portion 17, the optical bench 16, the first optical bench cover 19 and the ceiling mounting bracket 181 are attached to the back plate 18 in the same manner as in FIG. The cover portion 12 is fixed by fitting the second optical bench cover 15 into the opening portion 142 of the cover main body 14 . In the cover part 12 , an insect screen 155 is positioned just inside a smoke inlet 159 leading from the smoke inlet part 145 , and a gap between the circular opening 142 and the second optical bench cover 15 is closed by a flange 152 .

The smoke sensor 11 of this embodiment is assembled by detachably attaching body fixing screws 183 to the cover body 14 through the screw holes 182 of the back plate 18 . When cleaning, the smoke sensor 11 attached with the ceiling mounting bracket 181 is removed from the ceiling, and the two main body fixing screws 183 are removed from the screw holes 182, thereby separating the fixing portion 13 and the cover portion 12 as shown in FIG. do. As will be described later, the cover portion 12 has a cover main body 14 and a second optical bench cover 15 engaged therewith. In this way, the fixing portion 13 consisting of the first optical bench cover 19, the optical bench 16, the optical bench extension portion 17, and the back plate 18 exposes the lower surface of the first optical bench cover 19, making it possible to clean it. Further, for the smoke detection unit 165 , air can be ejected from the central opening 193 of the cover by an air duster or the like to remove dust accumulated on the upper surface of the first optical bench cover 19 and the inner wall surface of the optical bench 16 . A cleaning operator only needs to separate the smoke sensor 11 into two parts, the fixed part 13 and the cover part 12, and does not need to remove other parts, which facilitates the work.

FIG. 8 is an oblique projection view of the upper surface of the cover portion 12 in Embodiment 2 of the present invention. When the cover portion 12 is removed from the fixed portion 13, the inside of the second optical bench cover 15 is exposed as shown in FIG. 8, and the second optical bench cover 15 can be cleaned. Dirt such as dust can be removed from the inside of the second optical bench cover 15 using a cloth, an air duster, or the like. Further, the second optical bench cover 15 is fixed to the cover main body 14, so that the second optical bench cover 15 will not come off during the cleaning work. Therefore, it is possible for the cleaning operator to remove the dust accumulated inside the cover part 12 with an air duster or the like, which facilitates the cleaning work. After cleaning, the cover part 12 is attached to the fixed part 13 again.

Next, locking and the like of the cover main body 14 and the second optical bench cover 15 will be described. 8 shows the screw receiver 149, the inclined portion 141, and the locking post 147 of the cover main body 14, the second cover bottom portion 153, the central projection 157, the annular convex portion 158a, and the insect screen of the second optical bench cover 15. 155, rim 151, flange 152 and projecting plate 156 are shown. The screw receptacle 149 is a cylindrical body with holes for fixing body fixing screws 183 used when attaching the cover body 14 to the back plate 18. As shown in FIG. 141 are provided one by one at opposite positions when viewed from the center. The locking columns 147 are provided on the inclined portion 141 of the cover main body 14 one by one at opposing positions when viewed from the center, and the second optical bench cover 15 is fixed by the protruding plate 156 . The central portion of the locking post 147 is a hole for guiding the light of the confirmation lamp 173 to the confirmation lamp window 146 on the lower side of the inclined portion 141, and a transparent resin member penetrates vertically inside. It's stuck. A cross-shaped central projection 157 is provided on the upper portion of the second cover bottom portion 153 in the central portion of the second optical bench cover 15 . In the second cover bottom portion 153, the periphery of the central protrusion 157 is circularly protruded upward to form an annular protrusion 158a. An insect net 155, a peripheral edge portion 151, a flange 152, and an optical bench cover strut 154 shown in FIG. 7 are provided on the outer periphery of the second cover bottom portion 153. , forming a projecting plate 156 . The second optical bench cover 15 is fixed to the cover main body 14 by locking the projecting plate 156 to the locking column 147 .

FIG. 9 is an enlarged view of the locking column 147 portion of the top view of the cover portion 12 in Embodiment 2 of the present invention. FIG. 9 shows an inclined portion 141, a screw receiver 149, a locking column 147, a locking piece 148, a flange 152, a peripheral edge portion 151, a second cover bottom portion 153, and a projecting plate 156 of the second optical bench cover 15. , a projecting plate notch 156a is shown. FIG. 10 is an end view of the cover portion 12 in Example 2 of the present invention, cut along line DD shown in FIG. 10 shows inclined portion 141 of cover body 14, confirmation light window 146, opening 142, smoke inlet portion 145, protection plate 143, locking column 147, locking piece 148, and flange 152 of second optical bench cover 15. , the peripheral portion 151, the insect screen 155, the smoke inlet 159, and the depth of the protruding plate notch 156a in the protruding plate 156 are shown. 10, the transparent resin inside the locking column 147 is omitted.

As shown in FIG. 9, the projecting plate 156 is provided with projecting plate notches 156a, and as shown in FIG. The position of the base cover 15 is determined. As shown in FIGS. 9 and 10, the locking column 147 is provided with a locking piece 148 that locks the inner part of the projecting plate notch 156a to prevent the second optical bench cover 15 from coming off. . Specifically, the inclined portion 141 in the vicinity of the opening 142 supports the flange 152 from below, and the locking piece 148 presses the projecting plate 156 from above at the depth of the projecting plate notch 156a. Lock the inner part by sandwiching it vertically. Thus, the second optical bench cover 15 is fixed to the cover main body 14 .

When the second optical bench cover 15 is attached, the vertical surface of the protruding plate 156 extending from the flange 152 is warped inward, and the protruding plate 156 is fixed by the locking piece 148 at the position of the protruding plate notch 156a by the snap fit mechanism. be done. During installation, it is mainly the vertical portion of the protruding plate 156 that is distorted. As shown in FIG. Plastic deformation of the mesh 155 can be prevented. In addition, since the cover main body 14 and the second optical bench cover 15 can be attached and detached by distorting the protruding plate 156 inward, it can be removed and cleaned as necessary when the lower portion of the flange 152 or the like is extremely dirty. .

Next, the smoke flow path and external light blocking of the smoke detector of the second embodiment will be described. FIG. 11 is a vertically cut end view of the smoke sensor 11 in Example 2 of the present invention. FIG. 11 shows the cover main body 14, the second optical bench cover 15, the first optical bench cover 19, the optical bench 16, the optical bench extension portion 17, and the back plate 18. FIG. The inclined portion 141 of the cover main body 14, the protective plate 143, the smoke inlet portion 145, the second cover bottom portion 153 of the second optical bench cover 15, the central projection 157, the annular convex portion 158a, the insect screen 155, the smoke inlet 159, Flange 152, first cover disk 191 of first optical bench cover 19, thickened portion 192, cover central opening 193, and smoke detection portion 165 are shown. The annular convex portion 158a has a shape that obliquely rises from the outer circumference toward the center and then obliquely descends. In addition, the lower surface of the thick portion 192 obliquely descends from the outer periphery toward the center, and then ascends. The angle of descent is gentler than the angle of ascent. FIG. 12 is a bottom view of the first optical bench cover 19 in Example 2 of the present invention. FIG. 12 shows the first cover disc 191, the thickened portion 192, the cover central opening 193, the smoke introduction fins 194, and the first cover connecting portion 195. FIG. The first optical bench cover 19 is connected and fixed to the optical bench extension portion 17 by a first cover connecting portion 195 . FIG. 13 is a top view of the second optical bench cover 15 in Example 2 of the present invention. FIG. 13 shows the second cover bottom portion 153, the central protrusion 157, the annular convex portion 158a, the peripheral portion 151, the flange 152, the protruding plate 156, and the protruding plate notch 156a. The central projection 157 has a cross shape when viewed from above, and protrudes vertically upward from the central portion of the second cover bottom portion 153 .

Smoke from a fire enters the smoke sensor 11 from one of six annular smoke inlets 145 . Fire smoke passes through the smoke inlet 159 from the smoke inlet 145 shown in FIG. 11, passes through the insect screen 155, and enters the lower labyrinth of the smoke detector. The smoke flowing through the insect screen 155 advances toward the center of the fan-shaped space surrounded by the second cover bottom 153, the first cover disk 191 of FIG. 12, and the smoke introducing fins 194. Then, it passes over the annular projection 158a, passes through the gap between the second cover bottom portion 153 and the thick portion 192, and enters the central portion of the labyrinth lower portion. The smoke that reaches the central portion of the lower labyrinth is blocked by the central projection 157 to generate turbulent flow. As shown in FIG. 13, the central projection 157 is a cross-shaped wall that impedes the flow of air from the smoke inlet 159 in either direction. Then, the smoke passes through the central opening 193 of the upper cover and flows into the smoke detector 165 . In the smoke detector 165 in the upper part of FIG. 11, the light emitting element emits light intermittently, and the light receiving the smoke is sensed by the light receiving element as scattered light.

The smoke detector has a structure in which external light is blocked by the first optical bench cover 19 and the second optical bench cover 15 and cannot enter the smoke detector 165 . Outside light entering the smoke inflow part 145 shown on the left and right in the lower part of FIG. 11 from the outside of the smoke sensor 11 passes through the insect screen 155 from the smoke inflow port 159 and enters the labyrinth in the lower part of the smoke detector. At this time, external light incident from obliquely above the smoke inflow portion 145 is blocked by the annular convex portion 158a, and light incident obliquely below the smoke inflow portion 145 is blocked by the lower surface of the thick portion 192. does not pass through the cover central opening 193 and reach the smoke detector 165 . In this way, in the lower labyrinth formed between the first optical bench cover 19 and the second optical bench cover 15, the space through which the smoke passes is bent up and down, so that the outside light passes through the central opening 193 of the cover. The opening does not reach the smoke detector 165 in the upper layer. Although this structure alone can prevent outside light, in the second embodiment, the smoke introduction fins 194 shown in FIGS. ing.

According to the second embodiment of the present invention, when cleaning the inside of the two-layered smoke sensor 11, the cover body 14 and the second optical bench cover 15 can be integrally removed as the cover part 12. By exposing the inside of the device, dust can be removed with a cloth or an air duster. At this time, only the cover body 14 is required to be removed from the smoke sensor 11 by the cleaning operator, which facilitates cleaning. Further, since the cover body 14 and the second optical bench cover 15 are integrated, the cover body 14 and the second optical bench cover 15 can be attached at once after removing and cleaning. Further, even if air is blown onto the second optical bench cover 15 and the cover body 14 with an air duster or the like during cleaning, the second optical bench cover 15 will not fall off, and the cover portion 12 will not fall off. Also, the second optical bench cover 15 does not drop from the cover body 14. - 特許庁Therefore, cleaning work is easy. The connection between the second optical bench cover 15 and the cover body 14 is detachably attached using a snap-fit structure with a protruding plate 156 and a locking piece 148 . When attaching and detaching, it is the vertical surface of the protruding plate 156 that is distorted, and since the insect screen 155 is far from the position of the locking piece 148 and is less likely to be distorted, plastic deformation of the metal insect screen 155 can be prevented. . Since positioning is performed by the projecting plate notch 156a and the locking column 147, the positions of the second optical bench cover 15 and the cover main body 14 in the rotational direction are determined. Therefore, the optical bench cover post 154 is positioned inside the post 144 and does not block the inflow of smoke. Moreover, since the gap between the second optical bench cover 15 and the cover main body 14 is covered with the flange 152, it is possible to prevent a member such as a wire from being inserted from the opening 142 toward the optical bench extending portion 17 by mischief or the like.

In Example 2, the cover main body 14 has a plurality of locking posts 147 inside, and the second optical bench cover 15 has a plurality of projecting plates 156 on the sides. Then, the second optical bench cover 15 is locked to the cover main body 14 by fitting the locking column 147 into the projecting plate notch 156 a of the projecting plate 156 and pressing the projecting plate 156 with the locking piece 148 of the locking column 147 . , forming the cover part 12 . Also, the first optical bench cover 19 is fixed as part of the fixed part 13 . Since the cover portion 12 is detachably fixed to the fixed portion 13, the cover portion 12 is integrally removed from the fixed portion 13, and the exposed inside of the first optical cover 19 and the second optical cover 15 are separated. can be cleaned.

Further, in the second embodiment, an optical bench 16 housing a light emitting element and a light receiving element, a first optical bench cover 19 covering the optical bench 16, a second optical bench cover 15 covering the first optical bench cover 19, and a cover body 14 that covers the second optical bench cover 15 . The first optical bench cover 19 has a cover central opening 193 in the center, and a thick portion 192 around the cover central opening 193 that gradually becomes thicker on the lower surface side as the cover central opening 193 is approached. The second optical bench cover 15 has a cylindrical peripheral edge portion 151 , a plurality of optical bench cover support columns 154 , and a disk-shaped second cover bottom portion 153 . and the second cover bottom portion 153, a smoke inlet 159 opens. The second cover bottom portion 153 has an annular convex portion 158a projecting upward at a position outside the thick portion 192, and the upper surface of the annular convex portion 158a and the lower surface of the thick portion 192 prevent smoke from flowing. A labyrinth that moves the path up and down is formed to prevent external light from reaching the upper smoke detector 165 through the central opening 193 of the cover. In this way, the inside of the optical bench 16 is shielded from light by the first optical bench cover 19 and the second optical bench cover 15 .

<Modification of Example 2>
In the second embodiment, after the smoke sensor 11 is removed from the ceiling, the main body fixing screw 183 is removed to separate the fixed part 13 and the cover part 12, which are cleaned. The structure may be such that the interior can be cleaned without removing it from the ceiling. As in the modified example of the first embodiment, the second optical bench cover 15 and the cover main body 14 may be connected by using double-sided tape. Also in this case, the second optical bench cover 15 can be detachably fixed to the cover main body 14 with a simple configuration.
Further, in the smoke sensor 11 of Example 2, the cover body 14 has an opening 142 in the center of the inclined portion 141, and the protective plate 143 is attached via a plurality of struts 144 provided around the opening 142. By providing it, the smoke inflow part 145 has a shape protruding downward. However, the present invention is not limited to this and can be applied to various sensors. For example, the smoke inflow part 145 may be provided on the side surface of the cover body 14 and may be applied to a thin sensor in which the smoke inflow part 145 does not protrude downward.
In the second embodiment, the smoke is easily guided to the smoke detector 165 by the smoke introduction fins 194 and the central projection 157, but smoke can be detected without one or both of the smoke introduction fins 194 and the central projection 157. .
In Example 2, as shown in FIG. 11, a thick portion 192 is provided around the central opening 193 of the cover to block light. However, if the lower surface side of the first optical bench cover 19 is gradually lowered as the cover central opening 193 is approached, light can be blocked without increasing the thickness. In addition, although the light shielding property is higher when the annular convex portion 158a of the second optical bench cover 15 is provided, even without it, the periphery of the cover central opening 193 in the first optical bench cover 19 gradually descends from the outside and finally becomes oblique. If it is a structure that rises to the height, the smoke can be smoothly guided to the smoke detection section 165 while the smoke detection section 165 is light-shielded.
In the second embodiment, in the direction from the peripheral smoke inlet 159 toward the center, the lower surface of the first optical bench cover 19 gradually lowers near the center, and the upper surface of the second optical bench cover 15 gradually rises in the peripheral area. It has a structure that gradually descends. A labyrinth structure for blocking light is formed by vertically bending the space formed between the first optical bench cover 19 and the second optical bench cover 15 . However, if the space from the outer circumference to the opening provided in the first optical bench cover 19 is curved in the vertical direction, a light-shielding labyrinth can be obtained without the structure such as the annular convex portion 158a and the thick portion 192. can be done. For example, a small-radius cylinder may protrude downward from the first optical bench cover 19 and a large-radius cylinder may protrude upward from the second optical bench cover 15 . However, when the protruding portion has a sloped shape as in the second embodiment, the smoke is more likely to flow. Further, even if the first optical bench cover 19 does not protrude downward around the cover central opening 193 , the annular convex portion 158 a of the second optical bench cover 15 makes it difficult for outside light to reach the cover central opening 193 .

1 smoke sensor, 2 cover part, 3 fixed part, 4 cover main body, 41 inclined part, 42 opening, 43 protection plate, 44 strut, 441 strut inner convex part, 45 smoke inflow part, 46 confirmation light window, 47 snap Fit, 5 Optical Bench Cover, 51 Periphery, 52 Flange, 521 Flange Recess, 53 Optical Bench Cover Bottom, 54 Optical Bench Cover Post, 55 Insect Screen, 6 Optical Bench, 61 Labyrinth Wall, 62 Top Wall, 63 Light Emitting Element Cover , 64 light-receiving element cover, 7 substrate, 71 light-emitting element, 72 light-receiving element, 73 confirmation light, 74 substrate fixing screw, 8 back plate, 81 ceiling mounting bracket, 82 snap-fit connection port,
11 smoke sensor, 12 cover part, 13 fixed part, 14 cover main body, 141 inclined part, 142 opening, 143 protection plate, 144 strut, 145 smoke inflow part, 146 confirmation light window, 147 locking post, 148 locking Piece 149 Screw receiver 15 Second optical bench cover 151 Peripheral edge 152 Flange 153 Second cover bottom 154 Optical bench cover support 155 Insect screen 156 Protruding plate 156a Protruding plate notch 157 Central protrusion 158a annular convex portion, 158b annular concave portion, 159 smoke inlet, 16 optical bench, 165 smoke detection portion, 17 optical bench extension portion, 173 confirmation light, 174 board fixing screw, 18 back plate, 181 ceiling mounting bracket, 182 screw hole, 183 body fixing screw, 19 first optical bench cover, 191 first cover disc, 192 thick portion, 193 cover central opening, 194 smoke introduction fin, 195 first cover connection portion

Claims (3)

an optical bench housing a light-emitting element and a light-receiving element;
a back plate on which the optical bench is mounted;
an optical bench cover that covers the optical bench;
a cover body that covers the optical bench cover;
The cover main body includes an inclined portion having an opening, a plurality of pillars having one end connected to the opening side of the inclined portion and erected, and a protective plate connected to the other end of the plurality of pillars. and a smoke inlet surrounded by the opening, the strut and the protective plate,
the optical bench cover is detachably fixed by fitting a peripheral portion thereof to the inside of the support ,
A smoke detector, wherein the optical bench cover is removed from the optical bench integrally with the cover body when the cover body is removed from the back plate. an optical bench housing a light-emitting element and a light-receiving element;
a back plate on which the optical bench is mounted;
a first optical bench cover that covers the optical bench;
a second optical bench cover that covers the first optical bench cover;
a cover body that covers the second optical bench cover;
shielding the inside of the optical bench from light by the first optical bench cover and the second optical bench cover;
When the cover body is removed from the back plate, the second optical bench cover is integrally removed from the optical bench while the first optical bench cover is attached to the optical bench. A smoke detector characterized by being removed. The cover body has a locking post inside,
The second optical bench cover has a projecting plate on the side,
3. The smoke sensor according to claim 2 , wherein the locking piece of the locking column locks the projecting plate.

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