Fire detection device

Patent metadata

Field	Value
Publication number	US-12379313-B2
Application number	US-202318366039-A
Country	US
Kind code	B2
Filing date	Aug 7, 2023
Priority date	Jul 24, 2018
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

An occurrence space 32 A which is provided in a light shielding space 3 A shielded from light from an outside and into which a detection target flows, a first light emitting unit 61 A and a second light emitting unit that emit detection light along a first light emitting-side optical axis 611 A and a second light emitting-side optical axis toward an occurrence space 32 A, a light receiving unit that receives scattered light generated when detection light emitted from the first light emitting unit 61 A and the second light emitting unit is scattered by a detection target flowing into the occurrence space 32 A along a light receiving-side optical axis intersecting the first light emitting-side optical axis 611 A and the second light emitting-side optical axis, and a smoke detection unit cover-side inclined portion 43 A that primarily reflects the detection light emitted from the first light emitting unit 61 A and the second light emitting unit in a direction intersecting a plane defined by the first light emitting-side optical axis 611 A, the second light emitting-side optical axis, and the light receiving-side optical axis are included.

First claim

The invention claimed is:

1. A fire detection apparatus attached to an installation surface of an installation object for detecting a fire in a monitored area, comprising:
an inflow space provided in the fire detection apparatus, a gas on an outside of the fire detection apparatus being allowed to flow into the inflow space,
a detection space for detecting the detection target, the detection space being provided at a position on an installation surface side than the inflow space in the fire detection apparatus, and
an incidence suppression unit that inhibits ambient light from entering the detection space from the outside of the fire detection apparatus, the incidence suppression unit partitioning the inflow space and the detection space so that the gas is allowed to flow into the detection space through the inflow space, and inhibiting the ambient light from directly entering the detection space through the inflow space is allowed,
wherein the incidence suppression unit includes,
a first incidence suppression unit that accommodates the detection space, the first incidence suppression unit that is an inner cover being configured to cover at least a part of the detection space and partition a part of the inflow space,
a second incidence suppression unit that accommodates the first incidence suppression unit, the second incidence suppression unit that is an outer cover being configured to partition another part of the inflow space, and
an opening provided in a side portion on an opposite side from a side portion on the installation surface side in side portions of the first incidence suppression unit to allow the gas flowing into the inflow space to flow into the first incidence suppression unit,

wherein a first opening is provided on the installation surface side in the first incident suppression unit as the inner cover, the first opening being configured for sending gas flowing into the inflow space to the detection space, and gas can flow into the detection space through the first opening from the opposite side of the installation surface side,
wherein the first incidence suppression unit and the second incidence suppression unit are configured such that when the ambient light enters the detection space through the inflow space and the opening, the ambient light is allowed to be reflected a plurality of times with respect to the first incidence suppression unit or the second incidence suppression unit,
wherein the second incident suppression unit as the outer cover has a top surface portion located on a side farthest from the installation surface in the outer cover and a plurality of plate-shaped ribs,
wherein the inflow space is located between the top surface portion of the second incident suppression unit as the outer cover and the first incident suppression means as the inner cover,
wherein the plurality of ribs are disposed along a direction orthogonal to the installation surface in the inflow space, and
wherein the plurality of ribs is configured such that inflow of the gas flowing into the inflow space into the opening is not hindered by the plurality of ribs.

Assignees

• Hochiki Co

Inventors

• SHIMADZU Tomohiko
• Washizu Keisuke
• Dohi Manabu
• Fujiwara Yasuharu
• Takano Hideki

Classifications

• G08B17/113

  Constructional details · CPC title

• G08B17/107 Primary

  for detecting light-scattering due to smoke · CPC title

• F21V7/0025

  Combination of two or more reflectors for a single light source (array of reflectors for a cluster of light sources F21V7/0083) · CPC title

• G01N21/53 Primary

  within a flowing fluid, e.g. smoke · CPC title