JP7707056B2 - smoke detector - Google Patents

Description

This invention relates to a smoke detector.

In the case of photoelectric smoke detectors, the smoke detector is configured such that within the smoke detector section where the smoke is introduced, a light receiving element located in the smoke detector receives scattered light from the light emitting element located in the smoke detector, and detects smoke based on the amount of light received. They are primarily used as fire detectors, and are installed on ceilings or walls within buildings to be monitored. Specific examples of use include residential fire alarms and fire detectors for automatic fire alarm systems. Note that some residential fire alarms are configured as combined alarms that also detect gas leaks (leaks of city gas, etc.) and CO (carbon monoxide).

Smoke detectors are generally attached to an installation surface via a mounting base (see, for example, Patent Document 1).

JP 2012-226657 A

In this type of smoke detector, if a space is provided on the rear side of the detector housing (see, for example, FIG. 5 of Patent Document 1), an air flow is created that passes through the space on the rear side, causing smoke to flow out of the smoke detection unit into the space on the rear side, or outside air to flow into the smoke detection unit from the space on the rear side, which may dilute the smoke concentration in the smoke detection unit. In other words, if a space is provided on the rear side of the detector housing, there is a possibility that a delay in smoke detection may occur.

In view of the above circumstances, this invention aims to provide a smoke detector that can prevent delays in smoke detection even if there is space on the rear side of the detector housing.

This invention is a smoke detector in which a housing having a smoke detection unit inside is attached to an installation surface via a mounting base attached to the rear side of the housing, and is characterized in that on the rear side of the housing, on the inner side of the outer wall of the housing, a vertical wall is provided which forms an approximately circumferential shape along the periphery of the rear side of the housing , and a rear side space is provided which is surrounded by the vertical wall.

The present invention also provides a smoke detector in which a housing having a smoke detection unit provided therein is attached to an installation surface via a mounting base attached to its rear side, and the rear side of the housing has a roughly circumferential upright wall provided on the inner peripheral side of the outer peripheral wall of the housing, and a rear side space portion surrounded by the upright wall, the upright wall having a cut-out portion and an inner wall portion provided in an arc shape from both ends of the cut-out portion to the inner peripheral side so as to close the cut-out portion, and an operating portion is provided between the inner wall portion and the outer peripheral wall of the housing; or a smoke detector in which a housing having a smoke detection unit provided therein is attached to an installation surface via a mounting base attached to its rear side, and the rear side of the housing has a roughly circumferential upright wall provided on the inner peripheral side of the outer peripheral wall of the housing, and a rear side space portion surrounded by the upright wall , the mounting base is attached by covering the upright wall, and the rear side space portion is covered by the mounting base .

In this invention, a space is provided on the rear side of the housing as the rear space, and a substantially circumferential vertical wall is also provided surrounding the rear space. Therefore, the rear space can be closed by the vertical wall, which can prevent smoke from flowing out from the smoke detector into the rear space and prevent outside air from flowing into the smoke detector from the rear space.

Therefore, this invention provides a smoke detector that can prevent delays in smoke detection even if there is space on the rear side of the housing.

FIG. 1 is a perspective view of the front side of a smoke detector housing according to an embodiment of the present invention. FIG. FIG. 2 is a perspective view of the rear side of the sensor housing of the same. FIG. 2 is a rear perspective view of the sensor housing with the mounting base attached thereto; FIG.

An example of an embodiment of the smoke detector of this invention will be described below as smoke detector 1 with reference to Figures 1 to 5. The smoke detector of this invention can be used as a fire detector installed to monitor the interior of a building, etc., and specifically, can be used as, for example, a residential fire alarm (including a combined type having a function for detecting gas leaks, CO, etc.) or a fire detector for an automatic fire alarm system.

The terms "front" and "back" used to describe this invention and indicating position and direction are used according to the position and direction of the smoke detector 1 when it is installed.

[Device overview]
The smoke detector 1 is used as a residential fire alarm and has a smoke detector 7 inside its housing 2 (see FIG. 5). The housing 2 is made up of a main body 3 and a front cover 4 attached to its front side, and has a flat, thin shape overall with no protruding portion for the smoke detector on the front side. The main body 3 is made up of a base 5 and a middle plate 6 attached to its front side (see FIG. 5).

More specifically, the smoke detector 7 is provided on a circuit board 9 provided on the rear side of the middle plate 6, and is exposed from the rear side to the front side through a through hole provided in the middle plate 6 when the middle plate 6 is attached to the base 5 (see FIG. 5). Around the smoke detector 7, on the front side of the middle plate 6, a flow path wall 10 is provided (see FIG. 5) that forms a smoke flow path 11 that guides smoke flowing in from a smoke inlet 4a provided in the outer peripheral wall 4b of the front cover 4 toward the smoke detector 7. The smoke detector 7 detects smoke that is guided in by the smoke flow path 11.

The smoke detector 1 is attached to an installation surface such as a ceiling or wall of a building to be monitored via a mounting base 20 (see FIG. 4) attached to the rear side of the housing 2, and issues an alarm when the smoke detection unit 7 detects smoke exceeding a predetermined concentration occurring in the building to be monitored.

The mounting base 20 is made up of a bottom wall portion 20a and a peripheral wall portion 20b, and is generally cylindrical with a bottom, with its inner surface being the side to which the housing 2 is attached and its rear surface being the side to which the mounting base 2 is attached (see FIG. 4).

[Vertical wall, rear space]
Basic configuration In the smoke detector 1, an outer peripheral wall 4b of the front cover 4, which is an example of an outer peripheral wall of the housing 2, is provided on the rear side of the housing 2, and a roughly circumferential standing wall 12 is provided on the inner side of the outer peripheral wall 4b, and a rear space portion 13 surrounded by the standing wall 12 is provided.

In the smoke detector 1, a space is provided on the rear side of the housing 2 as the rear space 13, and a vertical wall 12 is also provided that is approximately circumferential and surrounds the rear space 13. Therefore, the rear space 13 can be closed off by the vertical wall 12, preventing smoke from flowing out from the smoke detection unit 7 into the rear space 13 and preventing outside air from flowing into the smoke detection unit 7 from the rear space 13. Therefore, even if a space is provided on the rear side of the housing 2, delays in smoke detection can be prevented.

Specific examples of the standing wall and rear space portion - Arrangement of the standing wall, etc. In the illustrated example, the rear surface of the base portion 5 of the main body 3 forms the rear surface of the housing 2, and the standing wall 12 is erected in a substantially circumferential shape along the periphery of the rear surface of the base portion 5. The front side of the main body 3 is covered with the front cover 4, and in this covered state, the standing wall 12 is located on the inner circumferential side of the outer peripheral wall 4b of the front cover 4.

Relationship with the mounting base The mounting base 20 is attached to the rear side of the housing 2 in a state where it is fitted around the standing wall 12, and the rear space 13 is covered by the mounting base 20 (see FIG. 4). The peripheral wall 20b of the mounting base 20 is located on the outer periphery of the standing wall 12 and, together with the standing wall 12, closes the periphery of the rear space 13 to prevent smoke from flowing out from the smoke detection unit 7 into the rear space 13 and to prevent outside air from flowing into the smoke detection unit 7 from the rear space 13.

The mounting base 20 is attached to the rear side of the housing 2 by fitting them together. In the illustrated example, the base 20 is attached by fitting an insertion piece 20c provided on the inner surface of the bottom wall 20a of the mounting base 20, which can be inserted and removed by rotating, to a receiving portion 12d provided on the top of the peripheral wall 12a (described later) of the vertical wall 12 of the housing 2 (see Figures 2 to 4).

...Notch in the standing wall, inner wall, and operation unit More specifically, the standing wall 12 has a peripheral wall 12a, which forms a substantially circumferential shape, and further has a notch 12b formed by removing a portion of the peripheral wall 12a, and an inner wall 12c connected to the peripheral wall 12a and arcing from both ends of the notch 12a toward the inner side so as to close the inner periphery of the notch 12b (see Figs. 2 and 3). The peripheral wall 12a and the inner wall 12c are both provided on the rear surface of the base 5 as the standing wall 12, and an operation unit 14 for various settings (initial settings, etc.) is provided on the rear surface of the base 5 in the notch 12b closed by the inner wall 12c (see Figs. 2 and 3).

The operation unit 14 is operated when the mounting base 20 is not attached to the rear side of the housing 2. In this case, the provision of the cutout portion 12b in the vertical wall 12 makes it easier to access the operation unit 14, improving its operability. And while the operability can be improved in this way, the space on the inner periphery of the cutout portion 12b is closed by the inner wall portion 12c on the inner periphery, so that it is possible to prevent smoke from the smoke detector 7 from flowing out into the rear space portion 13 through the space on the inner periphery of the cutout portion 12b, and to prevent outside air from flowing into the smoke detector 7 from the rear space portion 13. In addition, the space on the inner periphery of the cutout portion 12b is also closed by the peripheral wall portion 20b of the mounting base 20 on the outer periphery, so that it is possible to prevent smoke from flowing out of the smoke detector 7 into the rear space portion 13 through the space on the inner periphery of the cutout portion 12b, and to prevent outside air from flowing into the smoke detector 7 from the rear space portion 13.

In the illustrated example, the missing portion 12b is completely free of any wall-like portion, but it may be a cut-out portion with a wall-like portion remaining. Specifically, the cut-out portion may be formed by cutting out the top side of the peripheral wall portion 12a of the standing wall 12 while leaving the base side as a wall-like portion.

More specifically, the rear space 13 is formed between the mounting base 20 and the inner surface of the bottom wall 20a. In the illustrated example, the vertical wall 12 is provided at a height such that the top of the peripheral wall 12a substantially reaches the inner surface of the bottom wall 20a of the mounting base 20 when the mounting base 20 is attached to the housing 2. This is because the mating parts of the housing 2 and the mounting base 20 are located at the top of the peripheral wall 12a of the standing wall 12 and on the inner surface of the bottom wall 20a of the mounting base 20. However, the standing wall 12 (including the peripheral wall 12a and inner wall 12b) and the peripheral wall 20b of the mounting base 20 both close the periphery of the rear space 13 to prevent smoke from the smoke detector 7 from escaping into the rear space 13 and to prevent outside air from flowing into the smoke detector 7 from the rear space 13. Therefore, it is preferable that the heights of both are such that they at least overlap on the inside and outside when the mounting base 20 is attached to the housing 2 and the peripheral wall 20b of the mounting base 20 is located on the outer periphery of the standing wall 12.

It is preferable that the height of the inner wall portion 12c is approximately the same as that of the peripheral wall portion 12a, but in the illustrated example, it is made lower than the peripheral wall portion 12a (see FIG. 3). This is to avoid interference by the inner wall portion 12c when the housing 2 and the mounting base 20 are fitted together.

Furthermore, when the front cover 4 is placed on the front side of the main body 3, the standing wall 12 is located on the inner periphery of the outer periphery wall 4b of the front cover 4, and the operating unit 14 is located between the inner wall portion 12c of the standing wall 12 and the outer periphery wall 4b of the front cover 4, but on the rear side of the main body 3 with the front cover 4 placed on it, the outer periphery wall 4b of the front cover 4 is arranged so that the wall height is lower than the peripheral wall portion 12a of the standing wall 12 (see FIG. 3). As a result, even when the front cover 4 is placed on the front side of the main body 3, it is possible to easily access the operating unit 14 through the cutout portion 12b of the standing wall 12, improving its operability.

[Battery compartment]
The housing 2 is provided with a battery storage section 15 in which a battery is stored (see FIGS. 2 and 3). The battery storage section 15 is provided in the base section 5 of the main body 3, and in the illustrated example, a part of the battery storage section 15 in the thickness direction is provided so as to protrude into a rear space section 13 on the rear side of the base section 5 (see FIGS. 2 and 3). In other words, the rear space section 13 is used as an arrangement space section for the battery storage section 15. The battery storage section 15 is provided so as to protrude also on the front side of the base section 5 on the opposite side, but since the battery storage section 15 protrudes into the rear space section 13, the protrusion width toward the inner surface side of the base section 5 can be reduced (see FIG. 5).

As a result, the internal layout of the housing 2 allows the space on the middle plate 6, where the smoke detector 7, smoke flow passage 11, etc. are located, and the battery storage section 15 to be arranged at different levels in the thickness direction, and the battery storage section 15 can be arranged in a position where it does not protrude into the space on the middle plate 6, where the smoke detector 7, flow passage wall 10, smoke flow passage 11, etc. are located, through which smoke flows (see FIG. 5). In other words, the battery storage section 15 can be arranged in a position where it does not interfere with the flow of smoke.

[Example of changing the configuration]
Although an embodiment of the present invention has been described above with reference to FIGS. 1 to 5, the specific configuration is not limited to the above embodiment, and design changes and the like are also included within the scope of the gist of the present invention.

1: Smoke detector 2: Housing 3: Main body 4: Front cover 4a: Inlet 4b: Outer wall 5: Base 6: Middle plate 7: Smoke detector 9: Circuit board 10: Flow path wall 11: Smoke flow path 12: Standing wall 12a: Peripheral wall 12b: Notched portion 12c: Inner wall 12d: Receiving portion 13: Rear space 14: Operation portion 15: Battery storage 20: Mounting base 20a: Bottom wall 20b: Peripheral wall 20c: Insertion piece

Claims (3)

A smoke detector in which a housing having a smoke detection unit therein is attached to an installation surface via a mounting base attached to a rear side of the housing,
A smoke detector characterized in that a vertical wall is provided on the rear side of the housing, the vertical wall being approximately circumferential along the periphery of the rear side of the housing , and a rear side space portion is provided which is surrounded by the vertical wall. A smoke detector in which a housing having a smoke detection unit therein is attached to an installation surface via a mounting base attached to a rear side of the housing,
A substantially circumferential standing wall is provided on the rear side of the housing on the inner peripheral side of the outer peripheral wall of the housing, and a rear side space portion surrounded by the standing wall is provided,
The standing wall has a cutout portion and an inner wall portion that is provided in an arc shape from both ends of the cutout portion toward an inner periphery so as to close the cutout portion,
A smoke detector comprising : an operating unit provided between the inner wall portion and an outer peripheral wall of the housing. A smoke detector in which a housing having a smoke detection unit therein is attached to an installation surface via a mounting base attached to a rear side of the housing,
A substantially circumferential standing wall is provided on the rear side of the housing on the inner peripheral side of the outer peripheral wall of the housing, and a rear side space portion surrounded by the standing wall is provided,
A smoke detector characterized in that the mounting base is attached by being placed around the upright wall, and the rear space is covered by the mounting base.