CN113269944A - Smoke detector - Google Patents

Abstract

The invention relates to a smoke detector, which comprises a temperature sensor, a smoke sensor, a guide device, a base and an upper cover, wherein the guide device is arranged on the base, the temperature sensor and the smoke sensor are positioned between the base and the guide device, the upper cover is arranged on the guide device, the temperature sensor is arranged in the middle of the guide device of the smoke detector, the smoke sensor is arranged at an eccentric position of the guide device relative to the temperature sensor, the guide device is provided with a plurality of ribs which extend towards the periphery of the smoke detector and can guide the smoke direction, and the plurality of ribs are converged at a convergence point above the smoke sensor, so that the smoke is guided into the smoke sensor through the guide device. The smoke detector has the advantages of good directivity, flexible arrangement, particularly strong universality and the like, and can effectively improve the smoke inlet characteristic, so that the smoke detector has basically consistent response to smoke in all directions.

Description

Smoke detector

The application is a divisional application of Chinese patent application with application number 201310501612.4 and invention name "smoke detector" filed on 23/10/2013.

Technical Field

The present invention generally pertains to the field of fire safety and more particularly relates to a smoke detector.

Background

U.S. patent application US7616126, assigned to Gentex corporation, by Brain j. Kadwell et al, proposes a particle sensor. This patent discloses a particle detector that includes a light source, a photosensor, and a controller, wherein the controller is in communication with the light source and the photosensor. The controller is configured to reject substantially all signals except those generated by the light source.

Chinese utility model patent CN2831098Y, transferred by wangwangqing et al to shenyang fire research institute of ministry of public security, proposes a particle-counting smoke detector. The patent discloses a particle meter formula smoke detector, including laser instrument, laser beam space correction lens, light beam space filter tube, detection room, laser instrument support, smog detection lens subassembly, smog detector bracket component, smog scattering detector, smog detector fault detection luminotron, leaded light hole, reflecting plate.

One smoke detector is proposed in european patent application EP2166520a1 by SAKAMOTO et al, assigned to Panasonic Electric Works, inc. The smoke detector has a smoke sensing chamber around which a plurality of labyrinth walls are formed, wherein a light emitting portion and a light receiving portion are provided in the form of: the light receiving portion is in a position where light is not directly received from the light emitting portion, thereby configuring a smoke sensing area and a smoke inlet is formed in a wall of the labyrinth, and the detection sensor is adapted to discriminate a flame by detecting light scattered by smoke entering the smoke sensing chamber through the smoke inlet.

U.S. patent application US2006/007010A1, assigned to Zhexin Mi et al and Tyco Safety Products Canada, Inc., proposes a method for calibrating a smoke detector. The method disclosed in this patent includes adjusting the sensitivity of the smoke detector to achieve a continuously predetermined response throughout the run.

U.S. patent application No. US4171486 to John Dobrzanski et al, and Emhart Industries, ltd, proposes an ion smoke detector with controlled sensitivity. The ion smoke detector disclosed in this patent is provided with a vented sensing chamber and a housing having an opening disposed in the annulus and an open guide mounted within the annulus.

U.S. patent application US4845474 to pretice g. Moore et al, Pioneer Manufacturing, ltd, proposes a smoke and flame detector. The ion smoke and flame detector disclosed in this patent includes a nodal ring for supporting a vibrating plate.

U.S. patent application US4864141 to Jacques Lewiner et al provides a smoke detector. The smoke detector disclosed in this patent is provided with an ionization chamber.

U.S. patent application No. 5,310,51034 to Horst Berger et al, assigned to Esser sicherithstenik limited, proposes a flame detector. The flame detector disclosed in this patent comprises a scattering photodetector unit and an ion detection unit disposed on a common base at each side of a central axis of a compartment defined by the base and a peripheral wall extending from the base.

US patent application US5400014 to George e, Behlke et al, and Detection Systems limited, proposes a smoke detector. The smoke detector disclosed in this patent includes a dark room structure surrounded by a peripheral wall having a plurality of vanes. The second element of each blade is shorter than the first element and intersects the first element.

U.S. patent application US5995008 to John d. King et al, assigned to Detector Electronics limited, proposes a photo-flame Detector. The detector disclosed in this patent includes two or more sensors that operate with different spectral bands.

US patent application US6377182, assigned to BRK branches ltd, Mark a, Devine et al, proposes a smoke detector. The detector disclosed in this patent has a geometry that positions the sensor or sensors at or near the boundary layer of smoke travel.

US patent application US7075445, assigned to GE Security ltd by David k, Booth et al, proposes a smoke detector. The detector disclosed therein has a light source that emits a light beam that propagates to a detection chamber formed by a first optical component and a second optical component.

US patent application US7075646 published by Martin Terence Cole proposes a smoke detector. The smoke detector disclosed therein detects particles suspended in a fluid, is mounted in a duct and alternately illuminates a detection zone (12) by a first or second illumination (11).

Prior art smoke detectors typically employ a geometrically symmetric guide as shown in FIG. 1. Because the intersection point a' of the guiding device is not aligned with the detection area of the smoke sensor, the traveling path of smoke is greatly hindered, the response of the smoke detector in all directions is inconsistent, and the scattering capacity of white smoke to light is greater than that of black smoke, the response of the detector to the white smoke is sensitive, but the response to the black smoke is slow, so that the problems of false alarm of the white smoke, leakage alarm of the black smoke and the like are easily caused. Still other existing smoke detectors achieve a balance of sensitivity in each direction by sacrificing smoke performance, which, while consistent directivity can be achieved to some extent, can cause the detector to respond with a lag and to be sensitive to wind speed.

Disclosure of Invention

In view of the above, according to a first aspect of the present invention, there is provided a smoke detector that effectively solves the above-mentioned and other problems of the prior art. In a smoke detector according to the present invention, the smoke detector includes a temperature sensor, a smoke sensor, a guide means, a base, and an upper cover, the guide means is provided above the base, and said temperature sensor and said smoke sensor are located between said base and said guide means, and said upper cover is disposed over said guide means, wherein the temperature sensor is disposed at a middle portion of the guide means of the smoke detector, and said smoke sensor is arranged at an eccentric position of said guiding means with respect to said temperature sensor, the guiding means has a plurality of ribs extending towards the periphery of the smoke detector that can guide the orientation of smoke, the plurality of ribs meet at a meeting point located above the smoke sensor so as to guide smoke into the smoke sensor by the guide means.

In one embodiment of the smoke detector according to the invention, the upper cover is integrally formed with the guide means.

In another embodiment of the smoke detector according to the invention, a plurality of windows for the entrance of smoke are provided at the side of the upper cover, wherein each window is located between two adjacent ribs.

In a further embodiment of the smoke detector according to the invention, the guiding means are arranged symmetrically along a line connecting the centres of the temperature sensor and the smoke sensor.

In another embodiment of the smoke detector according to the invention, said ribs are arranged at equal angular intervals.

In another embodiment of the smoke detector according to the invention, the guiding means is made of plastic.

In yet another embodiment of the smoke detector according to the present invention, one of the plurality of ribs is disposed along a middle portion of the guide means.

In a further embodiment of the smoke detector according to the invention, a mounting frame for mounting the temperature sensor is provided on the one rib

In another embodiment of the smoke detector according to the invention, the number of ribs is eight.

In yet another embodiment of the smoke detector according to the invention, the width of the ribs is the same.

In yet another embodiment of the smoke detector according to the invention, the smoke sensor is a dual optical path photosensor.

The technical scheme provided by the invention has the beneficial effects that: compared with the prior art, the smoke detector provided by the invention adopts the eccentrically arranged guide device, so that smoke can be effectively and quickly guided to the upper part of the smoke sensor, the smoke inlet path is greatly improved in terms of functionality, and the response of the smoke detector to the smoke in all directions is basically consistent.

Drawings

The technical solution of the present invention will be described in further detail with reference to the accompanying drawings and examples. Wherein:

fig. 1 is a schematic view of a smoke detector of the prior art with part of the upper cover omitted.

Figure 2 is a schematic diagram of the structure of one embodiment of the smoke detector of the present invention with part of the upper cover omitted.

Figure 3 is a schematic view of the guide and cover of the smoke detector of figure 2.

Figure 4 is a radar plot of the smoke detector of figure 1 with response thresholds as coordinates.

Figure 5 is a radar plot of the smoke detector of figure 2 with response thresholds as coordinates.

Detailed Description

It is to be noted, firstly, that the structural configuration, characteristics and advantages of the smoke detector of the present invention will be specifically described below by way of example, however, all the descriptions are given for illustrative purposes only and should not be construed as forming any limitation on the present invention. Furthermore, any single feature described or implicit in each embodiment or shown or implicit in each drawing may continue to be combined or subtracted between any of the features (or their equivalents) to achieve still further embodiments of the invention that may not be directly mentioned herein.

The following detailed description of specific embodiments of the invention refers to the accompanying drawings. It should be noted that the terms of orientation such as up, down, left, right, front, back, top, bottom and the like mentioned or possibly mentioned in the present specification are defined with respect to the configurations shown in the respective drawings, and they are relative concepts, and thus may be changed accordingly depending on the positions and the use states thereof. Therefore, these and other directional terms should not be construed as limiting terms.

The invention provides a composite smoke detector which comprises a temperature sensor and a smoke sensor. In order to maximize the function of the temperature sensor, the temperature sensor is disposed at the middle portion of the entire smoke detector to rapidly detect the rising temperature. The smoke sensor can be a single-light-path photoelectric sensor with larger luminous flux or a double-light-path photoelectric sensor with more complex structure. The temperature sensor and the smoke sensor may be mounted on the base of the smoke detector at the same time. In order to be compatible with or avoid components such as a temperature sensor, the smoke sensor is eccentrically arranged on the smoke detector relative to the temperature sensor, so that the detection area of the smoke detector is not located in the middle of the whole smoke detector structure. An optical maze is arranged in the smoke sensor, and parts such as an indicator light, a photodiode, a plurality of transmitting tubes and receiving tubes are arranged in the optical maze. When smoke or smoke dust enters the optical maze, infrared light is received through the reflection and scattering receiving tubes, the intelligent alarm circuit judges whether the infrared light exceeds a threshold value, and if the infrared light exceeds the threshold value, an alarm is given out through the alarm controller. In order to show the connection relationship of the components more clearly, the components such as the temperature sensor, the smoke sensor, the base and the alarm controller are not drawn in the figure. It will be appreciated that the smoke detector of the invention is in practice inverted at the ceiling or wall etc.

As can be clearly seen in fig. 2, the smoke detector 1 further comprises guiding means 2 made of a material such as plastic. The guiding device 2 is composed of a plurality of ribs 3, the ribs 3 extend towards the periphery of the smoke detector 1 and are approximately in a spoke shape, and the junction point a of the ribs 3 is eccentrically arranged above the smoke sensor, so that the junction point a of the guiding device 2 is aligned with the smoke sensor, and the smoke is favorably guided to the detection area of the smoke sensor smoothly. For a dual optical path photoelectric sensor with forward scattering and backward scattering, the labyrinth structure in the smoke detector is quite complex, and it is conceivable that smoke is difficult to pass through where the gap is small in the labyrinth structure, so the smaller the gap is, the poorer the directional sensitivity is, and the gap above the labyrinth structure (i.e. the space where the guiding means 2 is located) is larger, so most of smoke will pass through the vicinity of the guiding means 2. Although the smoke inlet length in each direction is slightly shorter as seen in the figure, the smoke detector has better orientation and the response and sensitivity of the smoke sensor to smoke in each direction are basically consistent, but the smoke inlet length in each direction does not have larger influence on the response (namely, the response threshold value) of the smoke.

Referring to figure 3, there is shown schematically the basic structure of one embodiment of the guide means and cover in the present smoke detector. In this embodiment, the smoke detector 1 comprises a generally dome-shaped upper cover 4 to protect the guide 2 below the upper cover 4 and the smoke sensor and temperature sensor etc. on the base, wherein the upper cover 4 and the guide 2 may be integrally formed. The rib 3 thus acts like a reinforcing rib, and in addition to its guiding function, also serves to reinforce the upper cover 4. A plurality of windows 5 of generally rectangular shape are provided at the side of the upper cover 4 for the passage of smoke into the interior of the smoke detector 1, and each window 4 is located between two adjacent ribs 3 so that smoke entering from the windows 5 can be guided by the guide means 2. Preferably, the guiding means 2 are symmetrically arranged along the line connecting the centres of the temperature sensor and the smoke sensor (these guiding means may be asymmetrically distributed), and this symmetrical arrangement as shown in figure 2 not only provides a balance in terms of structure, but also, more importantly, it better guides the direction of the smoke, i.e. the smoke entering through the window 5 is guided uniformly and smoothly towards the middle of the smoke detector 1. In order to make better use of the limited internal space within the smoke detector and to make it more compact, the ribs 3 of the guide 2 are provided with mounting brackets 6 for mounting and fixing components such as temperature sensors or indicator lights, which are located below the guide 2.

In other embodiments combined with the above embodiments, the number of the ribs 3 of the guide device 2 is eight, and extends from the intersection point a toward the side of the upper cover 4 along the top contour of the upper cover 4 in an equiangularly spaced manner, and the width of the ribs 3 may be the same, as shown in fig. 3. Of course, the number of ribs 3 of the guide device 2 is not limited to eight, and other numbers of ribs 3, for example five, six, seven or more, may be provided on the upper cover 4, and the arrangement or shape and size of these ribs 3 may be flexibly designed in different situations to meet the requirements of different smoke detectors. For example, one of the plurality of beads 3 may be provided along a middle portion of the guide 2 in order to increase the structural strength of the guide 2 at the middle position thereof.

Further, experiments verify that the difference between the response threshold of the existing smoke detector and the response threshold of the smoke detector of the invention is large, and meanwhile, the radar charts shown in fig. 4 and 5 are compared to obtain that when the smoke detector actually works, the response thresholds of the smoke detector adopting the guiding device of the invention in all directions are basically consistent, and obviously, the smoke detector of the invention has better orientation and sensitivity.

In summary, the smoke detector of the present invention improves the smoke inlet path, and by aligning the smoke inlet central area with the detection area, that is, by disposing the intersection point of the guiding device above the detection area of the smoke detector, the smoke inlet paths in all directions are substantially consistent and the sensitivities thereof are substantially the same while ensuring the best operation effect of the temperature sensor. It is emphasized that the present invention achieves uniform directionality by directing smoke flow rather than blocking the entry of smoke flow in certain favorable orientations, and thus the directionality is particularly good, effectively overcoming the problem of high sensitivity of scattering type photosensors to detect white smoke and poor sensitivity to black smoke. Therefore, the smoke detector is especially suitable for a double-optical-path photoelectric sensor with a complex structure. In addition, for a smoke detector equipped with a plurality of sensors such as a temperature sensor and a smoke sensor at the same time, the advantages in fire alarm are more apparent in terms of directivity, or more precisely, sensitivity in each direction.

While the smoke detector of the present invention has been described in detail with reference to the several embodiments, these embodiments are merely illustrative of the principles and implementations of the invention, and are not to be construed as limiting the invention. Accordingly, all equivalents are intended to be included within the scope of this invention and defined in the claims which follow.

Claims (11)

1. A smoke detector, characterized in that the smoke detector comprises a temperature sensor, a smoke sensor, a guiding device, a base and an upper cover, the guiding device is arranged on the base, and said temperature sensor and said smoke sensor are located between said base and said guide means, and said upper cover is disposed over said guide means, wherein the temperature sensor is disposed at a middle portion of the guide means of the smoke detector, and said smoke sensor is arranged at an eccentric position of said guiding means with respect to said temperature sensor, the guiding means has a plurality of ribs extending towards the periphery of the smoke detector that can guide the orientation of smoke, the plurality of ribs meet at a meeting point located above the smoke sensor so as to guide smoke into the smoke sensor by the guide means.

2. A smoke detector according to claim 1, wherein said cover is integrally formed with said guide means.

3. A smoke detector according to claim 2, wherein a plurality of windows for ingress of smoke are provided at the sides of the upper cover, each window being located between two adjacent ribs.

4. A smoke detector according to any of claims 1-3, wherein said guiding means are arranged symmetrically along a central line connecting said temperature sensor and said smoke sensor.

5. A smoke detector according to any one of claims 1-3, wherein said ribs are arranged at equal angular intervals.

6. A smoke detector according to any of claims 1-3, wherein said guiding means is made of plastic.

7. A smoke detector according to any one of claims 1-3, wherein one of said plurality of ribs is located along a middle portion of said guide means.

8. A smoke detector according to claim 7, wherein said one web is provided with a mounting bracket for mounting said temperature sensor.

9. A smoke detector according to any of claims 1-3, wherein the number of ribs is eight.

10. A smoke detector according to any of claims 1-3, wherein the width of the ribs is the same.

11. A smoke detector according to any of claims 1-3, wherein said smoke sensor is a dual optical path photosensor.

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