JPH02240529A - Flame 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 (Industrial Application Field) The present invention relates to a flame detection snowmaking system for detecting the outbreak of a fire or the like by utilizing a flame fluctuation phenomenon.

(Prior Art) Since the flame generated by a fire has fluctuations, it is known to focus on this and detect the flame by using the level fluctuation frequency of the signal from the infrared detector as a detection parameter. However, outside light, especially sunlight, also contains components in the infrared region, and changes in the intensity of light rays reflected from reflective objects such as window glass that vibrate minutely due to vibrations and wind also change in the same way as the fluctuation of flames. Therefore, there was a problem in that detection errors were caused due to the influence of this.

In order to solve this problem, as shown in Figure 4,
This infrared detector A and a plurality of visible light sensors B, B! arranged around it. The output from each sensor A and B is amplified by high gain amplifiers C and D, the fluctuation of external light is removed by a phase comparator E, and the signal processing circuit F is used to amplify the output of a specific frequency, usually 3 to 30 Hz. It has been proposed to detect presence/absence. (Unexamined Japanese Patent Publication No. 19724/1983 Σ
Since flame detectors like this are usually mounted on ceilings or walls, when commercializing them, they must be as compact as possible and designed with design in mind. is required.

Figure 5 shows an example of a conventional flame detector, which has a bowl-shaped case with a light introduction window K fixed to the center of which is a transparent plate J that transmits infrared light and visible light. In addition, an infrared detector, a sensor chamber component M housing visible light detectors B and 8, a 'IIl source circuit board N, a shield plate P, and a signal processing circuit board Q are accommodated therein.

That is, the sensor chamber component M is fixed to the case L so as to face the light introduction window K, the visible light detectors B are fixed to this via the detector mounting plate St, and the case L1 is mounted A power supply circuit board N is fixed to the installed support T, a shield plate P is fixed to the top of this via a support U, and a signal processing circuit board Q is fixed to the support V roughly above the shield plate P, and the detection A conductive wire X was used to connect between the device B and the signal processing circuit board Q, and between the power supply circuit board N and the signal processing circuit board Q.

By the way, when an instrument 1 equipped with such a light introduction window K is used for a long period of time, dust in the air adheres and the light transmittance decreases, so the light introduction window must be cleaned at regular intervals. Requires. For this reason, disassembly work is required to remove the circuit board etc. from inside the case and expose the window member. Based on this, the shield plate P, signal processing circuit board Q, etc. are fixed by corner screws, so it is necessary to remove these parts in order, and it is said that disassembly and reassembly will be required. There was a problem.

The present invention has been made in view of these problems, and its object is to provide a flame detector H that simplifies disassembly and assembly operations.

(Meaning! Means for Solving) In order to solve such problems, the present invention has a bowl-shaped case body with a light introduction window in the center of the bottom, and a sensor chamber component that can be inserted through the center. A power supply circuit board, which is made up of a board with a through hole for closing and mounting power supply circuit components thereon, and a sensor chamber component equipped with a sensor housing shell are fixed in the center, and an infrared detection sensor is attached to the housing shell. means, and a signal processing circuit board to which a visible light detector is fixed;
A shield member located between the power supply circuit board and the signal processing circuit board and fixed to the signal processing circuit board, and a lid plate for sealing an opening of the case body, the power supply circuit board and the signal processing circuit The board was fixed to the case body.

(Function) Since the infrared detector, visible light detector, shield plate, and sensor chamber components are integrally attached to the signal processing circuit board, by pulling out the signal processing circuit board from the case, the infrared detector, visible light The detector, the shield plate, and the sensor chamber components can be pulled out at the same time, and the light guide plate 1FEIl can be pulled out through the through hole of the power circuit board. Further, when assembling the signal processing circuit board, the signal processing circuit board is set in its original position and the assembly is completed in an operable state by simply fixing the single plug, thereby simplifying the disassembly and assembly work.

(Example) The details of the present invention will be described below based on illustrated examples.

Figure 1.2 shows an embodiment of the present invention, in which reference numeral 1 is a bowl-shaped case body made of synthetic resin, with a through hole 2 bored in the center bottom. A light-transmitting plate 3 capable of transmitting infrared light and visible light is fixed by a holding member 4 to form a light introduction window 5, and a power supply circuit board 11 and a signal processing circuit board as described above are mounted on the side nitrogen part 6. 35 at a fixed distance, that is, at a distance that allows the connector 15.47 to fit.
7.7.8.8.8 is provided, and the conductive layer 1 is roughly coated on the entire inner surface.
01Fr is formed.

11 is the above-mentioned power supply circuit board, and the sensor chamber component 2
A substrate 13 having a through hole 12 drilled in the center thereof through which the material 1 is inserted.
A switching regulator circuit component (not shown) is mounted on the top, and a connector for connecting to an external circuit or a signal processing circuit board is mounted on the upper side in the figure when arranged in the case body 1. It is fixed to the case body 1 with screws 17 while being fixed and supported by the pillars 7.7.7.

19 is an aluminum shield plate for static electricity and electromagnetic shielding placed between the power supply circuit board 1] and the signal processing circuit board 350, and the light introduction window 5 is provided on the surface that faces downward when installed in the case body 1. The sensor chamber constituting member 21 is fixed with a screw 22 at an opposing position, that is, at the center, and a notch 25.25 is formed at a position facing the connector 15.16.

The sensor chamber component 21 is made of metal or a synthetic resin material with a conductive layer 23 on its surface, and has an infrared detector housing body 27 in the center and an integral chamber 29 formed to surround it. Visible light detector housing bodies 31, 31 arranged at equal intervals are formed in the upper part, and a diffuser plate 33 is provided at the tip.
It is configured to be fixed at 1Fr.

Reference numeral 35 designates the aforementioned signal processing circuit board, which is set in the case body 1 and has a sensor chamber component 21 integrally fixed to the shield plate 19 with screws 20 in the center of the downward facing surface, and is used for infrared detection. A pyroelectric infrared detector 37 that selectively detects light with a wavelength of 4.3 um, for example, is located at a position facing the container housing body 27, and a visible light detector housing body 3
A visible light detector 39 is attached at a position opposite to 1. In the center of this circuit board 35, the case body 1
A first-stage amplifier circuit (not shown) for amplifying the signal from the detector 37 and 39 is intensively mounted on the side that becomes the top surface when set to A phase detection circuit component (not shown) is mounted on the outer periphery of this, and a connector 47 is fixed at a position facing the connector 15 of the power supply circuit board 11. This circuit board 35 has its connector 47 fitted with the connector 15 of the power supply circuit board 11, is supported by the supports 8 of the case side wall 6, and is fixed to the case body 1 by screws 49.

Reference numeral 51 designates a cover plate made of synthetic resin, on which a conductive layer 53 is formed on the inner surface, and a shield wire 58 of a shield cable 55 connected to an external snowmaking device is formed on this conductive layer 53.
is connected.

At the stage when all the components are housed and fixed in the case body 1,
Connect the connector 57 of the shielded cable 55 to the power circuit board 1
1, the cover plate 51 is set in the opening of the case body 1, and both are fixed with a hissing member 59 or the like. As a result, the case body 1 and the cover plate 51 are connected to the conductive layer 10.53.
The connected state is established through @, and the entire case is grounded through the shield wire 58 of the shield cable 55. The infrared detector 37 and the visible light detector 39 are connected to the sensor chamber component 2
The circuit on the signal processing circuit board 35 is shielded by the conductive layer 23 of 1 and the shield case 41 on the top surface, and the circuit on the signal processing circuit board 35 is
The shield plate 19 and the shield are protected.

In this embodiment, in the absence of flame, infrared components contained in outside light, especially sunlight, are detected by an infrared detector 37, and visible light components are detected by a visible light detector 39.3.
9.39, the signal is converted into an electrical signal and input to the processing circuit on the signal processing circuit board 35. At this time, even if the incident external light has a fluctuation component with the same frequency as the flame,
Since both the infrared component and the visible light component have the same fluctuation and are in the same phase, they cancel each other out and do not cause false detection.

On the other hand, when a flame occurs, the flame contains an infrared component that is much stronger than the visible light component compared to external light. It will not be canceled by signals from other sources and will be reliably detected.

If the transparent plate 3 forming the light introduction window 5 becomes cloudy due to long-term use, the case body 1 may be removed from the cover plate 51.
If the signal processing circuit board 35 is fixed to the case body 1 after removing it from the case body 1, the signal processing circuit board 35 can be removed from the case body 1 by removing the screw 49. When the signal processing circuit board 35 is pulled out from the case body 1 in this state,
The connectors 15 and 47 are automatically disconnected, and the infrared detector 37, visible light detector 39, shield plate 19, sensor chamber component 21, and diffusion plate 33 fixed to the signal processing circuit board 35 are integrated. The light introduction window 5 is exposed through the through hole 12 in the center of the power supply circuit board 11 (Fig. 3). It becomes possible to clean both sides.

After cleaning is completed, the connector 57 of the shielded cable 55 is fitted to the connector 16 of the board 11, and the signal processing circuit board 35, the connector 47 attached thereto, and the connector 15 of the power supply circuit board 11 are aligned. After that,
The signal processing circuit board 35 is attached to the support column 8 of the side wall portion 6 of the case main body.
8.8 and fixing it with the hinges 49 completes the assembly in an operable state.

(Effects of the Invention) As explained above, the present invention includes a bowl-shaped case body provided with one light introduction window in the center of the bottom, and a substrate provided with a through hole in the center through which a sensor chamber component can be inserted. A power circuit board having power circuit components mounted thereon and a sensor chamber component including a sensor housing shell are fixed in the center, and an infrared detection means and a visible light detector are fixed to the housing shell. a signal processing circuit board, a shield member located between the power supply circuit board and the signal processing circuit board and fixed to the signal processing circuit board, and a lid plate for sealing an opening of the case body, Since the power supply circuit board and signal processing circuit board are fixed to the case body, simply by removing the signal processing circuit board, the infrared detector, visible light detector, shield plate, and sensor chamber components can be integrated from the case. It can be pulled out and the light guide plate can be exposed through the through hole of the power circuit board. Further, when assembling the signal processing circuit board, the signal processing circuit board is simply set in its original position and secured with screws, and the assembly is completed in an operable state, thereby simplifying the disassembly and assembly work.

[Brief explanation of drawings]

FIG. 1.2 is a sectional view of an apparatus showing an embodiment of the present invention;
FIG. 3 is an exploded perspective view showing the component parts, FIG. 3 is a cross-sectional view showing a state in which the circuit board on the case opening side is removed, and FIG. 4.5 is a block diagram and a cross-sectional view, respectively, showing an example of a conventional flame detection device. be. 1...Case body 2...Through hole 3...Translucent plate 5...Light introduction window 6...Side wall part
7.8... Support column 10... Conductive layer 11
...Power circuit board 12...Through hole 15.
... Connector 17 ... Screw 19 ...
Shield plate 21...Sensor chamber constituent member 27...Infrared detector housing barrel 29...Integration chamber 31...Visible light detector housing barrel 33...Diffusion plate 35...・Signal processing circuit board 37...Infrared detector 39...Visible light detector 41...Shield case Fig. 1 Fig. 3

Claims (1)

[Claims] A bowl-shaped case body with a light introduction window in the center of the bottom, a power circuit board with power circuit components mounted on the board with a through hole in the center through which the sensor chamber components can be inserted, and a sensor. A sensor chamber constituent member having a housing shell is fixed at the center, and a signal processing circuit board having an infrared detection means and a visible light detector fixed to the housing shell, the power supply circuit board and the signal processing circuit. A shielding member located between the substrates and fixed to the signal processing circuit board, and a cover plate sealing an opening of the case body, the power supply circuit board and the signal processing circuit board being fixed to the case body. A flame detection device.