Fire alarm device

• US 5,670,938 A
• Filed: 05/16/1995
• Issued: 09/23/1997
• Est. Priority Date: 01/18/1991
• Status: Expired due to Fees

• Current Assignee: Hochiki Kabushiki Kaisha
• Original Assignee: Hochiki Kabushiki Kaisha
• Inventors: Ohtani, Shigeru, Ono, Takashi, Ishii, Hiromitsu
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US08/441,808
• Time in Patent Office: 861 Days
• Field of Search: 340/506, 340/587, 340/511, 340/588, 340/589
• US Class Current: 340/506
• CPC Class Codes: G08B 17/00 Fire alarms; Alarms responsive to explosion

Abstract

In a fire alarm device for detecting the physical quantities of substances arising from the outbreak of a fire and giving a fire alarm, membership functions showing the correlation between an arising quantities calculated by the detected physical quantities and the danger degree which a man would feel with respect to the physical quantities are preset, the danger degree with respect to the arising value calculated by the physical quantities actually detected by a detection means is obtained by using the membership functions, and an alarm and control in accordance with the danger degree is given. Therefore, there is provided a fire alarm device capable of judging the outbreak of a fire based on an actual fire situation and giving an alarm and control in accordance with the degree of danger which a man would feel with respect to the scale, situation and so on of the fire.

Claims

1. A fire alarm device for judging an outbreak of a fire and emitting an alarm, comprising:

detection means for detecting at least one physical quantity of physical quantities in form of temperature, smoke density and gas arising from the outbreak of the fire;

arising quantity calculating means for calculating heat release quantity smoke generation quantity, gas generation quantity and the like per unit time based on detection data transferred from said detection means;

membership functions table means for storing coefficients providing predetermined correlation between arising value per unit time, such as heat release quantity, smoke generation quantity and gas generation quantity and the danger degree which a person would feel with respect to said arising value;

danger degree calculating means for calculating the danger degree corresponding to the heat release quantity, the smoke generation quantity, gas generation quantity and the like calculated by said arising quantity calculating means based on said membership functions table means; and

judging means for determining the kind of an alarm to be emitted depending upon said danger degree calculated by said danger degree calculating means;

environment coefficient table means for storing coefficients providing environmental conditions such as size of a room and whether or not easy-burning materials are present, said danger degree calculating means calculating the danger degree based on said membership functions table means and the environment coefficient table means;

said detection means comprising a plurality of different detectors;

sampling means between said detectors and said arising quantity calculating means for scanning sequentially values from said different detectors and transmitting said values to said arising quantity calculating means;

said judging means including output pre-alarm means, output fire alarm means and output fire prevention devices control signal actuated in dependence on the danger degree calculated by said danger degree calculating means.

2. A fire alarm device for judging an outbreak of a fire and emitting an alarm, comprising:

detection means for detecting at least one physical quantity of physical quantities in form of temperature, smoke density and gas arising from the outbreak of the fire;

arising quantity calculating means for calculating heat release quantity smoke generation quantity, gas generation quantity and the like per unit time based on detection data transferred from said detection means;

membership functions table means for storing coefficients providing predetermined correlation between arising value per unit time, such as heat release quantity, smoke generation quantity and gas generation quantity and the danger degree which a person would feel with respect to said arising value;

danger degree calculating means for calculating the danger degree corresponding to the heat release quantity, the smoke generation quantity, gas generation quantity and the like calculated by said arising quantity calculating means based on said membership functions table means; and

judging means for determining the kind of an alarm to be emitted depending upon said danger degree calculated by said danger degree calculating means.

3. A fire alarm device for judging the outbreak of a fire and emitting an alarm as defined in claim 2, including environment coefficient table means for storing coefficients providing environmental conditions such as size of a room and whether or not easy-burning materials are present, said danger degree calculating means calculating the danger degree based on said membership functions table means and the environment coefficient table means.

4. A fire alarm device for judging an outbreak of a fire as defined in claim 2, wherein said detection means comprises a plurality of different detectors;

sampling means between said detectors and said arising quantity calculating means for scanning sequentially values from said different detectors and transmitting said values to said arising quantity calculating means.

5. A fire alarm device for judging an outbreak of a fire as defined in claim 2, wherein said judging means includes output pre-alarm means, output fire alarm means and output fire prevention devices control signal actuated in dependence on the danger degree calculated by said danger degree calculating means.