JPS5894094A - Thermal fire detector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects heat caused by a fire and activates a reflective part intervening in the optical transmission path of the optical 7 eyeper using a heat-receiving part such as an inverted bimetal or a pneumatic diaphragm that displaces. This invention relates to a thermal fire detector that detects the sound of a fire by blocking the transmission of light.

In conventional fire alarm systems, a fire detector is connected to a power signal pulled out from a receiver, and a switch contact is closed when a change in physical phenomena such as heat or smoke due to a fire is detected. A fire detection signal is sent to the receiver so that a fire alarm is received and displayed.

By the way, in conventional fire detectors, 24 volts DC voltage is generally supplied from the receiver via the power supply signal #lt, so it is not suitable for use in places filled with explosive gas or in explosion-proof areas where open flames are strictly prohibited. The only solution is to install a fire detector that requires a power supply, and there are no other effective fire detection methods. Furthermore, conventional fire detectors that use continuous signals are susceptible to various types of induced noise.

Malfunctions of fire alarm systems caused by this noise are a problem, and there is a need for a radical solution that will not cause malfunctions due to noise.

The present invention has been made in view of the above, and has an inherently explosion-proof structure that does not provide peace of mind with regard to power supply, has high fire detection sensitivity, and can completely eliminate the influence of various electrical noises. The purpose of this invention is to provide a thermal fire detector with excellent safety and reliability.

The present invention will be explained below based on the drawings.

FIG. 1 is an explanatory diagram showing an example of the detection principle in the fire detector of the present invention. First, to explain the configuration, sensor 1
Inside is the reception J1! Light emitting optical fibers 2 and 1 that guide the light χ from the provided light source and output the incident light Lt'4
Emitted light LtY from the light emitting optical fiber 2: A light-receiving optical fiber 3 that receives the reflected light Lrg from the plane -4 and sends it to the receiver side is provided.
Reference numeral 4 is attached to a heat receiving/responsive part 5 which is displaced when heat from a fire is detected.

The detection action is such that in a normal monitoring state, when the heat-receiving/responsive part 5 is in a stationary position as shown in the figure, the emitted light Lt from the light-emitting optical fiber 2 is reflected at point P of the plane mirror 4, resulting in one reflected light beam. It enters the receiving side optical fiber 3 as Lr, and is transmitted to the receiver I.
IK has been sent. Meanwhile, the sensor body 1 was damaged due to heat from the fire.
When the ambient temperature rises to a predetermined knitting density, the reflector 4 is displaced by 4' ftK due to thermal deformation of the heat receiving/responsive part 5, and the radiation light L
Since the light t was reflected at point P', it did not enter the light receiving optical fiber 3, and the light from the light receiving optical fiber 3 was blocked. A fire is detected by detecting it on the receiver side.

Fig. ta2 is characterized by fire detection in the fire detector of the present invention, and the surface of an inverted bimetal 60 that receives the emitted light Lty from the light-emitting optical fiber 2 is made into a reflective surface 61 by mirror finishing or aluminum vapor deposition. The inverted bimetal 6 is formed by laminating, for example, a Mn-Cu-Ni joint member with a high expansion height and a 36% Ni-Fe joint member with a low expansion coefficient.

The detection action is to input the light reflected at point P of the inverted bimetal/L/6, which is curved upward at room temperature, into the light-receiving optical fiber 3), and when the inverted bimetal 6 reaches a specified temperature due to a fire. When heated.

Due to the difference in expansion coefficient, the inverted bimetal 6 deforms as shown by the broken line 6' and the reflection point becomes P', so the emitted light Lt from the light emitting optical fiber 2 becomes the light receiving light 7 eye A-3. A fire is detected when the light does not enter the receiving fiber 3 and the light is blocked.

Fig. 3 is an explanatory diagram showing another embodiment of the detection principle in the fire detector of the present invention. In the detection principle shown in Fig. 1.2, the reflection part is actuated by the displacement of the heat receiving response part in the event of a fire. However, in this embodiment, the end st' of the optical fiber is blocked by thermal deformation of the heat-receiving responsive part, thereby blocking the light from entering the light-receiving optical fiber. It is characterized by the following.

First of all, when purchasing, the heat receiving response section 5tC* is installed.
The tip of a composite optical fiber 70 containing a plurality of original fibers shown in FIG.
The composite optical fiber 7 has a light-receiving optical fiber 7 in the center, and a plurality of light-emitting lights 7 are arranged around it.

Therefore, in the steady monitoring state, the emitted light from the light-emitting optical fibers 7b located around the composite optical fiber 7 is reflected by the thousand-faced tablet 4 and enters the light-receiving optical fiber 71 located at the center.

When it receives heat from the fire, the heat-receiving response section 5 moves upward to the position of the plane mirror 4v4' and blocks the end face t of the composite optical fiber 7, thereby preventing the reflected light from entering the light-receiving optical fiber 78. Detect fire by blocking.

Figure 5 has the same detection source QK as in Figure 3, and is characterized by using an inverted bimetal 6V as a heat-receiving/responsive part. The end face of the composite optical fiber 7 is blocked by the deformation of the inverted pie metal 6 into the shape 6' shown by the broken line due to the heat generated during the fire.

The 6th eIA is the 55th! This shows a modified example of J, in which the inverted bimetal 6 is made into a υ cantilever structure by the fixed IS8, and similarly, the end face of the composite optical fiber 7 is deformed by the heat of a fire. Fires are detected by blocking them.

In this way, the fire detector of the present invention detects fire by reflecting the light from the light source guided by the optical 7 eyeper at the reflection part and sending it back to the receiver via the optical fiber.

Sometimes the reflective part due to heat response @! Fire is detected when the light from the fire detector is cut off and the light from the fire detector is cut off. There is no need to install a power supply unit for the sensor on the machine, and since the signal is sent and received by optical transmission, it has an essentially explosion-proof structure,
The influence of C, @ conduction noise, etc. is completely eliminated.

FIG. 7 shows an embodiment of the present invention based on the above-mentioned detection principle, and shows nine cross sections.

The structure consists of a sensor body 1 made of a plastic case, etc.
An optical connector 10 for connecting an optical fiber cable 9 from the outside is provided inside.

For example, a composite optical fiber 7 (hereinafter referred to as "original fiber") having the structure shown in FIG. An inverted bimetal 6t is housed in a heat-sensitive chamber 12a formed at the center of the plate 12, and the fiber end face side of one inverted bimetal/I/6 is a reflective surface 6m.

The fiber fixing portion 11 is provided with a vertical position adjustment mechanism for adjusting the distance between one end face of the fiber and the reflecting surface 6a, which will be explained later.

Next, to explain the action, in the steady microscopic state lll, the inverted bimetal 6 has its arms bent as shown.

The light from the light source guided through the optical fiber cable 9t is reflected by the reflective surface 61 of the inverted bimetal 60 and sent back to the receiver side through the optical fiber cable 9v.

Next, the heat collecting plate 12 receives heat from the fire, and the heat sensitive chamber 12a
When the inner inverted bimetal 6 is heated to a predetermined temperature 1, for example, 75°C, the 1 inverted bimetal 6 inverts as shown in the figure 6' and blocks the end face of the light 7 eyer 7, blocking the transmission of the reflected light by the 1 reflection ift6g. The transmission of light to the receiver side is then cut off, and the receiver side detects the interruption of the light, thereby displaying a fire alarm.

FIG. 8 is a sectional view showing another embodiment of the present invention, and this embodiment is characterized in that the movement of the inverted bimetal in the embodiment of FIG. 7 is further expanded.

That is, the pressing piece 13af of the leaf spring 13 supported cantilevered on the fiber fixing part 11 is in white contact with the inverted bimetal 6 at the heat-sensitive chamber t2as'c of the heat collecting plate 12, and the f11ffiK of the optical fiber 7 is opposed to the tip of the leaf spring 13. Reflection @
114 is provided, and it is changed to 5.

The other configurations are the same as the embodiment shown in FIG.

Its action is that when the inverted bimetal 6 is inverted due to heat from a fire, the push-up piece 13 is pushed upward by the leaf spring 13 due to the heat, and therefore the reflecting part 14 is tilted at a large angle with respect to the end face trap of the optical fiber 7. , the emitted light from the optical fiber 7 is reflected in a direction away from the end face, and transmission of light to the receiver side via the optical fiber cable 9 is blocked.

FIG. 9 is a sectional view showing another embodiment of the present invention using an air diaphragm as the heat-receiving and sensitive portion.

First, to explain the configuration, the sensor body 1 houses an optical fiber 7 which is connected to an optical fiber cable 9V optical connector 10 by a fiber fixing part 11.
A chamber 15 forming a heat-sensitive surface Y and an air chamber 17 partitioned by a diaphragm 16 are formed on the lower side of the main body 1.
1] 7 is the leak flower material 18 attached to the diaphragm 16 side
A reflecting mirror 14 is attached to the center of the diaphragm 16 facing the end face of the optical fiber 7.

Next, to explain the operation, when the external temperature change is gradual, even if the pressure changes due to the expansion and contraction of the air in the air chamber 17 due to the temperature change, the air passing through the small holes of the leak flower material 18 will not flow. The pressure in the air chamber 17 is maintained at the external pressure by the entry/exit trap, and the diaphragm 16 is not deformed, and the light from the light source reflected by one reflection @ 114 is sent back to the receiver side via the optical fiber cable 9. It has been returned.

-75, When a sudden temperature rise occurs due to a fire.

The pressure in the air chamber 17 increases as the air flows out through the small holes of the leak flower material 18, and the diaphragm 16 expands and deforms upward, causing the 1-reflector 14 to close to the end surface of the optical fiber 7. This prevents the light from being reflected by the receiver, and the transmission of the light to the receiver side is blocked, and a fire alarm is issued in response to the blocking of the light.

FIG. 10 is a sectional view showing another embodiment of the present invention,
This embodiment is characterized in that it has a so-called compensating type heat sensing structure, which is provided with an inverted bimetal that inverts at a predetermined temperature, in addition to the diaphragm type embodiment of FIG. 9.

That is, with the diaphragm method shown in FIG. 9, it is not possible to detect fires in cases where the temperature rises slowly, such as in a smoke-burning fire. The center part of the diaphragm 16 is supported by the push-up bottle 20 that is pushed up by the reversal, and the reflecting mirror 14 is pushed up either by the reversal of the bimetal 60 or by the thermal expansion of the diaphragm 16, so as to block the end face t of the optical fiber 7. This is what I did.

Each of the embodiments shown in Figures 7 to 10 is similar to Figures 1, 2 or 3.
, 5 is used, but it goes without saying that the other detection principle may be used in the same way.

FIG. 11 is an explanatory diagram showing an embodiment of an optical fiber vertical position adjustment mechanism provided in the fiber fixing section 11 of FIGS. 7 to 10. In other words, in the fire detector of the present invention, it is necessary to adjust the position of one end face of the optical fiber so that the light reflected from the reflective part is maximized.The vertical position adjustment mechanism is extremely important in order to maximize the detection sensitivity. It is.

1! ! In FIG. 11, the optical fiber 7 is housed in a fiber holder 21, a rack 22 is formed in the fiber holder 21, and is attached to the fiber fixing part 11 so as to be movable up and down. The supported pinion gear 23 is meshed, and by turning the pinion gear 23v in a predetermined direction with a screwdriver or the like, the fiber holder 2-1 is moved up and down, and the position is adjusted so that the reflected light from the mirror 14 is maximized.

FIG. 12 shows another embodiment of the vertical position adjustment mechanism used in the present invention. In the embodiment of FIG. 11, adjustment is made by inserting a screwdriver from the side and turning the binion gear 23v. In this embodiment, in order to adjust the position by inserting the driver from above, the worm gear 24'1, which rotates on a vertical axis, is engaged with the rack 22 of the fiber holder 21. . Note that the worm gear 24 moves the rack 22 in the vertical direction f! 111m as it does not rotate depending on the
There is an advantage that positional deviation t is less likely to occur later.

FIG. 13 shows another embodiment of the vertical position adjustment mechanism used in the present invention, in which an optical fiber 7v is housed and fixed in a fiber holder 21 having a flange 26 that slides on a guide wall 25 lowered to which the fiber is fixed. , adjustment screw 27%' passes through the fiber fixing part 11 and screws into the flange 26 of the fiber holder 21, and the coil spring 2
8V is applied, and the fiber holder 21 is moved up and down by rotating the adjustment screw 270.

FIG. 14 shows another embodiment of the vertical position adjustment mechanism, in which a crimping member 29Y is attached to the fiber holder 21:
A threaded portion 31 formed on the fiber fixing portion 11 is fixed to prevent the cap nut 30t' from being removed and is rotatably attached.
Depending on how the cap nut 30 is screwed in, the upper and lower R'
I'm busy coordinating things.

As explained above, according to one aspect of the present invention, light emitted from a light source is guided into the sensor main body through a transmitting fiber and reflected by a reflecting section, and the reflected light is transferred to a receiving optical fiber. When heat from a fire is detected, the displacement of the heat-receiving response part activates the reflection part to prevent the reflected light from transmitting to the receiving optical fiber. Therefore, it has an essentially explosion-proof structure that can be placed as is in areas filled with explosive gas, etc., and there are no restrictions on installation location, and malfunctions due to induced noise etc. are completely eliminated. (1! Reliability is significantly same as above.

Furthermore, since it is sufficient to operate the reflector using a conventional heat-receiving/responsive part such as a one-inversion bimetal or an air diaphragm, the structure is simple, and when original fiber cables become common, equipment costs can be significantly reduced.

Furthermore, since there is no part t that causes deterioration over time, excellent durability can be obtained.

[Brief explanation of drawings]

Figures 1.2-3.4.5 and 6 are explanatory diagrams showing the detection principle of the present invention, Figure 7 is a cross-sectional explanatory diagram showing an embodiment of the present invention, and Figures 8.9 and 1o are Cross-sectional explanatory views showing other embodiments of the present invention, Figures 11, 12, 13 and 14 are upper and lower I! of the optical fiber used in the present invention. It is an explanatory view showing an example of an adjustment mechanism. 1...Sensor body 2.7b-...Optical fiber for light emission 3.7a...Optical fiber for light reception 4...Plane mirror 5...Heat-receiving response II 6-Inverted bimetal 61...Reflecting surface 7...・Composite optical fiber 8...fixing part 9...optical fiber cable 10...optical connector 11...fiber fixing part 12...heat collection plate 12m...thermal chamber 13-...plate spring 14- ...Reflector 15 River chamber 16...Diaphragm 17...
Air chamber 18...Leak flower material 20...Push-up pin 21...Fiber holder 22...Rack 23...Binion gear 24...?
#-A4A 26-...7 Lunge 27...Adjustment hissing 28...Coil spring 29...Caulking member 30...Applicant for bag nut patent Susumu Takeuchi, Hochigo Co., Ltd. Figure 5 Figure 7 Figure 8 Figure 9 Figure 11 Figure 12

Claims (1)

[Claims] A light transmitting optical fiber that guides and emits light from a light source,
A reflecting part that reflects the emitted light from the light transmitting optical fiber, a light receiving optical fiber that receives and transmits the reflected light from the reflecting part, and a light receiving optical fiber that receives and transmits the reflected light from the light transmitting optical fiber, and 1. A thermal fire detector comprising a heat-receiving response section that operates the reflection section so as not to transmit the emitted light from the light-use optical fiber to the light-receiving optical fiber.