JP3184397B2 - Photoelectric separated smoke detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoelectric separation type smoke detector in which a transmitter and a receiver for smoke detection are separated, and in particular, it is determined that normal monitoring cannot be performed after adjustment of an optical axis, an amount of received light, and the like. The present invention relates to a photoelectric separation type smoke detector that outputs a failure signal when the smoke signal is generated.

[0002]

2. Description of the Related Art Conventional photoelectric separation type smoke detectors include:
The optical axis is adjusted by looking at the other side from the rear side of the transmitter and receiver through the collimation hole, then adjusting the amount of received light by monitor output, and then monitoring the distance selection switch provided on the back side There is one in which the sensitivity is set by switching according to the distance.

That is, as shown in FIG. 7, first, in order to perform adjustment using a collimation hole, an optical axis fixing bracket 10 of a light transmitter is used.
2 is loosened, the main body is moved while looking through the collimation hole, and is substantially aligned with the center of the collimation hole 101 of the light receiver 100 to be paired, and the optical axis fixing bracket 102 is lightly tightened to the extent that the main body moves. Next, the light receiver 100 is similarly aligned with the center of the collimation hole of the light transmitter to be paired, and the optical axis fixing bracket 102 is lightly tightened.

Next, in order to adjust the monitor output (light reception amount), first, the monitor cover 103 of the light receiver 100 is adjusted.
Is opened, and check whether the monitor lamp in the set switch 104 is blinking. Next, the distance selection switch 105
To "Adjust". Next, monitor jack 106
Insert the attached monitor plug 107 into the tester 1
08.

Next, two output adjustment volumes 109,
At 110, adjustment is made so that the monitor output becomes an appropriate value.
Next, the transmitter main body and the light receiver 100 main body are slightly moved to find a position where the monitor output is maximum, and the optical axis fixing bracket 102 is tightened at that position to fix the transmitter main body and the light receiver 100 main body. I do.

[0006] Next, the distance selection switch 105 is switched to set the sensitivity in accordance with the monitoring distance, whereby a monitoring state is established. However, the photoelectric separation type smoke detector is
Since it is often mounted on a wall, it has been desired to be able to adjust the optical axis and set the sensitivity from the side or front.
As a result, the optical axis is adjusted with the front cover removed, and the initial value is registered, for example, by operating the adjustment switch provided on the side surface and operating the set button provided on the front surface after attaching the cover. There is one that performs the monitoring state.

That is, as shown in FIGS. 8 and 9,
In this photoelectric separation type smoke detector, the front cover 1
20 and the plug of the battery for the standby power supply of the receiver is connected to the connector 121 for connecting the external power supply.
The changeover switch 123 provided with the optical axis, the light amount, and the monitoring position provided on the side surface of the
Turn 4 to adjust the optical axis. Next, the distance setting switch 1
25 is set according to the monitoring distance, and after the changeover switch 123 is set to the “light amount” position, the light amount adjustment knob 126 is turned.

There are provided three light receiving amount display lamps 127, which indicate insufficient, appropriate, and excessive light receiving amounts, respectively.
Turn the light amount adjustment knob 126 to make adjustments so that an appropriate lamp blinks. When the insufficient lamp blinks, the light amount adjusting knob 126 is turned to the increasing side, and when the excessive lamp blinks, the light amount adjusting knob 126 is turned to the decreasing side. As described above, the amount of received light is adjusted by turning the light amount adjusting knob 126 while looking at the three received light amount indicating lamps.

After the adjustment of the optical axis and the amount of received light is completed, the changeover switch 123 is set to the "monitoring" position, the battery is removed, and the cover 120 is attached. Then, the initial setting is performed by pressing and holding the set button on the front of the light receiver for a predetermined time. As a result, the initial value is registered and a monitoring state is set. Also, JP-A-4-175999 and JP-A-4-82.
No. 789 describes that an operation unit for performing adjustment with a front cover removed is provided on a front surface of a light transmitter and a light receiver.

[0010]

However, in such a conventional photoelectric separation type smoke detector, although the optical axis can be adjusted and the amount of received light can be adjusted from the side or front, the optical axis, In the process of adjusting the amount of received light, if you close the cover with forgetting the sensitivity setting by the distance setting switch, if you set the sensitivity but forget to close the cover,
If you adjust the optical axis but forget to close the sensitivity setting and cover, if you only connect the power supply and do nothing afterwards, there was no function to inform you of these things, so the situation described above was completely I didn't understand. That is,
There is a problem in that when the monitoring state is set after the adjustment, it is impossible to understand at all that the monitoring is not normally performed.

The present invention has been made in view of such a conventional problem, and outputs a failure signal when it is determined that normal monitoring cannot be performed, such as when the sensitivity setting is forgotten during adjustment. The purpose is to inform the disability.

[0012]

FIG. 1 is a diagram illustrating the principle of the present invention. The present invention relates to a light transmitter 42 having a light emitting element 53.
And a photodetector 1 having a photodetector 54 are separately arranged, and a photoelectric separation type smoke detector for detecting light attenuation due to smoke between the photodetectors 1 is provided. Cover open / closed state determination means 76 for determining whether the cover is open / closed by turning on / off the cover open / close detection switch 36 that detects the open / close of the front cover that opens and closes to perform
Distance selection switch 37 for setting sensitivity according to monitoring distance
And a sensitivity setting state determining means 75 for determining the setting state of the cover, and detecting that the cover is closed in a state where the sensitivity setting is not set, or when the cover is set in a state where the sensitivity setting is set. A failure signal that outputs a failure signal to the receiver when it is detected that the cover has been opened for a predetermined time T2 or more, or when it is detected that the cover has been opened for a predetermined time T2 or more in a state where the sensitivity is not set. An output unit 77 is provided.

[0013]

According to the photoelectric separation type smoke detector of the present invention having such a configuration, the cover open / closed state determining means 76 for determining the cover open / closed state by turning on / off the cover open / close detection switch 36 and the monitoring distance. (1) When it is detected that the cover is closed in a state where the sensitivity setting is not set by the sensitivity setting state determining means 75 for determining the setting state of the distance selection switch 37 for setting the sensitivity (when the sensitivity setting is (2) When it is detected that the cover has been opened for more than a predetermined time T1 (for example, 5 minutes) in a state where the sensitivity setting is set (when the sensitivity is set but the cover is forgotten to be closed), (3) The cover is opened for a predetermined time T2 (for example, 2 hours) in a state where the sensitivity is not set, when the cover comes off due to some shock such as a ball hit. When the failure signal is detected (when the optical axis is adjusted but the sensitivity setting or the cover is forgotten, or only the power supply is connected and nothing is performed later), the failure signal is output by the failure signal output unit 77. Since the output is made to notify the person in charge of the occurrence of the above-described trouble, it is possible to reliably grasp that the monitoring cannot be performed normally.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 6 are views showing an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a light receiver of the photoelectric separation type smoke detector according to one embodiment of the present invention. The light transmitter is a light emitting element,
The configuration is the same except for some of the related circuits and components.

In FIG. 2, a photodetector 1 of a photoelectric separation type smoke detector is disposed on a side wall near a ceiling so as to be opposed to a light transmitter, and a housing is composed of a vertically long cover 2 and a main body 3. ing. The cover 2 is provided with a member that transmits near-infrared light but cuts visible light, for example, a window 2A made of polycarbonate. The cover 2 is configured to be vertically openable and closable with respect to the main body 3 by a cover fixing wire 4, a fixing metal 5, and a cover fixing metal 6. The optical axis / light receiving amount adjusting mechanism is housed. Further, the mounting plate 8 is screwed to the side wall near the ceiling, and the main body 3 is locked to the locking piece 8A of the mounting plate 8.

Next, the mechanism accommodated in the main body 3 will be described in detail. First, the base 9 of this optical axis / light receiving amount adjusting mechanism is formed of a metal fitting having an L-shaped side cross section.
Is fixed horizontally. Below the base 9, a shield case 10, a printed circuit board 11 on which light receiving circuit components are mounted, a power supply substrate 12, and an insulating sheet 1 for the light receiving substrate
3 are housed in a transparent circuit cover 14.

The base 9 has a fitting hole 9A in which an adjusting screw 20A for adjusting the horizontal direction of the lens holder 7 is fitted in the optical axis direction, the lens holder 7 and its supporting member 15A.
A shaft hole 9B for supporting the lens rotatably in the horizontal direction and a locking hole 9C for locking one end of a coil spring 16 for preventing the backlash in the horizontal direction such as the lens holder 7 are formed.

The shaft hole 9B of the base 9 has a separator 17
Is attached by the attachment screw 18 and the separator 1
Reference numeral 7 is configured to fit vertically to the flange portions 9D and 9E of the base 9 so as not to rotate in the horizontal direction. The separator 17 has a hole 17A through which one end of the coil spring 16 passes, a concave portion 17B for accommodating the coil spring 16 body, a shaft hole 17C, and the like.

The lens holder 7 is supported rotatably in the vertical direction with respect to a support member 15 having a U-shaped front section.
The support member 15 has the mounting screw 18 described above as an axis,
The shaft hole 9 of the base 9 is inserted through the shaft hole 17C of the separator 17.
B is attached to be rotatable in the horizontal direction. First, the horizontal rotation mechanism will be described. The support member 15 has a receiving screw 1 at a position deviated from the shaft hole 15A.
A locking hole 15B for locking the 9A in the vertical direction is formed, and a thread is formed in the receiving screw 19A so that the above-described horizontal adjustment screw 20A is screwed in the optical axis direction. I have. Therefore, when the adjustment screw 20A rotates, the support member 15 rotates in the horizontal direction around the mounting screw 18.

A locking hole 15C for locking the other end of the coil spring 16 in the vertical direction and an adjusting screw 20B for adjusting the vertical direction of the lens holder 7 are fitted in the supporting member 15 in the optical axis direction. The lens holder 7 is supported so as to be rotatable in the vertical direction about the screws 21 and 22 with respect to the support member 15. A coil spring 23 for preventing the vertical play of the lens holder 7 is attached to the lens holder 7.
One end of the coil spring 23 has the locking hole 1 of the support member 15.
5E, and the other end is locked to a locking piece 7A of the lens holder 7.

A receiving screw 19B is mounted on the side surface of the lens holder 7 at a position deviated from its rotation axis in the left-right direction, and the receiving screw 19A is attached to the receiving screw 19B.
Similarly to the above, a screw thread is formed so that the above-described vertical adjustment screw 20B is screwed in the optical axis direction. Therefore, when the adjustment screw 20 </ b> B rotates, the lens holder 7 rotates in a direction perpendicular to the support member 15. The lens holder 7 is provided with an aiming hole 7B for observing from obliquely forward and on the upper right of the front, and an aiming hole 7C is provided on the upper left of the front so as to be parallel to the optical axis direction.
A reflection mirror 7D for obliquely reflecting the visual field seen from the sighting hole 7B is attached. Reference numeral 7E denotes a lens held by the lens holder 7.

On the back side of the lens holder 7, a light receiving substrate 24 and a light receiving shield case 25 are fixed by screws 26 and 27. On both sides of the lens holder 7, light receiving amount adjusting knobs 2
8 and 29 are attached, and light reception amount adjustment knobs 28 and 29 are provided.
Adjusts the amount of received light by changing the photoelectric conversion voltage of the photoelectric conversion circuit. The received light amount adjustment knob 28 performs coarse adjustment, and the received light amount adjustment knob 29 performs fine adjustment.

Next, FIG. 3 is a front view of the light receiver 1 with the cover 2 removed. In FIG. 3, reference numeral 30 denotes the adjusting screw 20.
The optical axis adjustment knobs A and 31 are the optical axis adjustment knobs for the adjustment screw 20B, and the optical axis adjustment knobs 30 and 31 face the front because the adjustment screws 20A and 20B are both mounted in the optical axis direction. When the cover 2 is removed, it can be easily operated at a high place. When the optical axis adjustment knob 30 of the horizontal adjustment screw 20A rotates counterclockwise, the lens holder 7 rotates leftward, and when the optical axis adjustment knob 30 rotates clockwise, the lens holder 7 rotates. Turn right. When the optical axis adjustment knob 31 of the vertical adjustment screw 20B rotates counterclockwise, the lens holder 7 rotates downward, and when the optical axis adjustment knob 31 rotates clockwise, The lens holder 7 rotates upward.

The lens 7E is housed in the lens holder 7, and the lens holder 7 holds the support member 1 as described above.
5 so as to be rotatable in the vertical direction.
Is rotatably supported by the base 9 in the horizontal direction. A terminal nameplate 32 is attached to the front side of the circuit cover 14 below the separator 17 fixed to the base 9. The printed circuit board 11 is provided with an optical axis confirmation light 33 for confirming the optical axis. The optical axis confirmation light 33 is made up of a red LED, and blinks when the optical axis is adjusted to make it easy to see from the other party. Further, a fire indicator light 34 composed of an LED for indicating a fire is provided on the left side of the optical axis confirmation light 33 of the printed circuit board 11, and a failure indicator composed of an LED for indicating a failure is provided on the right side of the optical axis confirmation light 33. A lamp 35 is provided. Light emitted from the optical axis confirmation lamp 33, the fire indicator lamp 34, and the fault indicator lamp 35 is output to the outside through the transparent circuit cover 14 and the hole formed in the corresponding location of the terminal nameplate 32.

A cover opening / closing detection switch 36 for detecting the opening / closing of the cover 2 is provided on the lower surface of the circuit cover 14. The cover opening / closing switch 36 is a limit switch as shown in FIG. When cover 2 opens,
The cover open / close detection switch 36 is turned off, and when the cover 2 is closed, the cover open / close detection switch 36 is turned on. Also,
A distance selection switch 37 is provided on the lower surface of the circuit cover 14, and can be set to a specified sensitivity by setting it according to the monitoring distance. The distance selection switch 37 is composed of a dip switch.
m or more and less than 45 m, or 45 m or more and less than 100 m. The position where nothing is set is a position for adjustment.

On the lower surface of the printed circuit board 11, six chip LEDs 38A to 38F as monitor display means are provided.
Are arranged along the left-right direction. That is, LED
38A to 38F are mounted on the printed circuit board 11 so as to face obliquely when viewed from the front. When looking into the other party through the collimation hole during optical axis adjustment, LE
It is mounted diagonally to make it easier to see the light emission of D38A-38F.

These LEDs 38A to 38F include two yellow LEDs 38A and 38B, two green LEDs 38C and 38D, and two red LEDs 38
The LEDs 38A to 38F at positions corresponding to the light receiving levels are controlled to blink.
Therefore, the LEDs 38A to 38F constitute a light receiving level meter, and the photoelectric conversion voltage of the photoelectric conversion circuit is adjusted so that when the green LEDs 38C and 38D blink, an appropriate value is displayed.

That is, while checking the LEDs 38A to 38F, the light receiving amount adjusting knobs 28 and 29 are turned so that one of the two green LEDs 38C and 38D blinks. Thus, the vicinity of the center of the appropriate value of the received light amount is obtained, and the range of the received light amount is known. In addition, 39 is an insertion terminal part. Next, FIG. 5 is a block diagram of a light receiver and a light transmitter.

In FIG. 5, reference numeral 1 denotes the light receiver, and the light receiver 1 is connected to a light transmitter 42 via light transmitter control lines 40 and 41. The light receiver 1 is provided with a fire signal line 43,
It is connected to a receiver 46 via a common line 44 and a fault signal line 45. Reference numeral 47 denotes a constant voltage / current limiting circuit provided in the photodetector 1. The constant voltage / current limiting circuit 47 receives a power supply from the receiver 46, generates a constant voltage, and limits the power supply. Is supplied to each part. 4
Reference numeral 8 denotes a light emission control circuit for controlling the light emission operation of the light transmitter 42. The light emission control circuit 48 receives a constant voltage from the constant voltage current limiting circuit 47 via the diode 49 and emits light according to an instruction from the control unit 50. The control signal is transmitted to the light transmitter 42 via the light transmitter control line 41.

Reference numeral 51 denotes a light emission control detection circuit provided in the light transmitter 42. The light emission control detection circuit 51 detects a light emission control signal from the light receiver 1 and operates a light emission drive circuit 52. That is, the light emission control detection circuit 51
When the power supply is interrupted at a fixed interval, which becomes a light emission control signal by the control unit 8, the light emission drive circuit 52 is activated by negative logic. Therefore, the light emitting element 53 composed of an LED is
, And emits near-infrared light to the light receiving element 54 of the light receiver 1 in a pulsed manner via a lens.

Numeral 55 denotes an optical axis confirmation lamp driving circuit provided in the light transmitter 42. The optical axis confirmation lamp driving circuit 55 controls the light emission control signal from the light emission control detection circuit 51 and opens and closes the cover of the light transmitter 42. Is activated by an open signal (off signal) from the cover open / close detection switch 70 for detecting the light, and drives and blinks the optical axis confirmation lamp 56 composed of an LED. Reference numeral 37 denotes the distance selection switch provided in the photodetector 1, and the distance selection switch 37 outputs a signal set according to the monitoring distance and indicating a specified sensitivity to the control unit 50 via the sensitivity input circuit 57.
The controller 50 calculates a threshold value (fire level) based on the initial value, which is the light reception output after the cover 2 is closed, and the sensitivity setting after the cover 2 is closed, and stores it in the RAM 78 as a reference signal.

The control unit 50 compares the reference signal with the received light signal. If the received light signal is smaller than the reference signal, the controller 50 determines that a fire has occurred and outputs a fire signal to the fire signal detection circuit 71.
Reference numeral 36 denotes the cover open / close detection switch provided in the photodetector 1. The cover open / close detection switch 36 outputs an open signal (off signal) when the cover 2 is opened, and a close signal when the cover 2 is closed. (ON signal) is output to the control unit 50 via the cover opening / closing input circuit 58 and also to the oscillation circuit 59.

The oscillating circuit 59 receives the open signal from the cover open / close detection switch 36 and the constant voltage supplied from the constant voltage current limiting circuit 47 to generate a 5V voltage. Oscillating operation is performed based on the above, and an oscillating output is given to the optical axis checking lamp control circuit 61. The optical axis confirmation light control circuit 61 blinks the optical axis confirmation light 33 based on the oscillation output from the oscillation circuit 59 and the open signal from the cover opening / closing input circuit 58.

At the time of monitoring, when the control unit 50 detects a fire (for example, a dimming rate of 70% or more continues for a predetermined time),
By outputting the signal to the fire signal detection circuit 71, a fire signal is sent to the receiver 46. In this state, even if a failure due to interruption is detected (for example, a dimming rate of 90% or more continues for a predetermined time or more), the control unit 50 does not output a failure signal because a fire has been detected. .

The fault signal output cutoff circuit 62 cuts the fault signal from the control unit 50 based on the output from the fire signal detection circuit 71. Basically, the control unit 50 performs
This is not necessary because the failure signal is not output, but is provided so that the failure signal is not output to the receiver 46 even if it is output erroneously. The control unit 50 detects a failure due to the interruption (for example, the dimming rate 90
When% or more continues for a predetermined time or more), the failure signal is output to the failure signal output circuit 63, and the failure signal is sent to the receiver 46.

When a failure due to interruption is detected or when it is detected that normal monitoring cannot be performed, a failure signal is output from the control unit 50, and the failure signal causes the failure indicator light 35 to blink the occurrence of the failure. The fault signal output circuit 63 sends a fault signal to the receiver 46 via the fault signal line 45. On the other hand, when detecting the fire signal from the control unit 50, the fire signal detection circuit 71 turns on the fire indicator light 34 via the diode 64 and sends the fire signal to the receiver 46 via the fire signal line 43. .

Numeral 54 denotes the light receiving element formed of a photodiode provided in the light receiving device 1. The light receiving element 54 receives near-infrared light emitted from the light emitting element 53 of the light transmitter 42 in a pulsed manner. The light receiving element 54 and the variable resistor 72 constitute a photoelectric conversion circuit 65. The light receiving signal is transmitted to the photoelectric conversion circuit 6
The signal is converted into an electric signal by the amplifier 5 and amplified by the amplifier circuit 66. By turning the light receiving amount adjustment knobs 28 and 29, the resistance value of the variable resistor 72 is changed to change the photoelectric conversion voltage and increase or decrease the light receiving amount. The analog electric signal amplified by the amplifier circuit 66 is held by the peak hold circuit 73 and then enters the control unit 50 via the received light amount input circuit 74.
The control unit 50 is configured by an IC, and has an A / D converter 68 built therein. The analog electric signal is converted into a digital value by the A / D converter 68.

The control unit 50 has a drive table 69 for driving the LEDs 38A to 38F as the monitor display means.
The controller 50 drives the LEDs 38A to 38F with reference to the contents of the drive table 69. Here, the control section 50 is provided with a sensitivity setting state determination section 75 as sensitivity setting state determination means, and the sensitivity setting state determination section 75 is a dip serving as the distance selection switch 37 for setting the sensitivity according to the monitoring distance. Determine the switch setting.

Further, the control unit 50 is provided with a cover open / closed state determining unit 76 as cover open / closed state determining means for determining whether the cover is open / closed by turning on / off the cover open / close detection switch 36 for detecting opening / closing of the cover 2. The cover open / closed state determination unit 76 determines that the cover 2 is open when the cover open / closed detection switch 36 is off, and determines that the cover 2 is closed when the cover open / closed detection switch 36 is on.

Reference numeral 77 denotes a fault signal output unit as fault signal output means provided in the control unit 50. The fault signal output unit 77 outputs a fault signal when any of the following states is detected. (1) When detecting that the cover 2 is closed in a state where the sensitivity setting is not set (when the sensitivity setting is forgotten). (2) When it is detected that the cover 2 has been opened for a predetermined time T1 (for example, 5 minutes) or more with the sensitivity setting set (if the sensitivity is set but the cover is forgotten to be closed, something will be performed later) Shock, for example, when the cover comes off due to a ball hit). (3) When it is detected that the cover 2 has been opened for a predetermined time T2 (for example, 2 hours) in a state where the sensitivity has not been set (the optical axis has been adjusted, but the user forgets to set the sensitivity or close the cover 2). If you just plug in the power and do nothing afterwards).

The fault signal is output to the fault signal output circuit 63 through the fault signal output cutoff circuit 62, transmitted from the fault signal output circuit 63 to the receiver 46, and the fault indicator 35 blinks. Next, the operation will be described. FIG. 6 is a flowchart illustrating the operation of the control unit 50.

In FIG. 6, first, data is taken in at step S1. That is, light is received by the light receiving element 54,
The received light amount input through the photoelectric conversion circuit 65, the amplification circuit 66, the peak hold circuit 73, and the received light amount input circuit 74 is taken in. The detected light amount is detected by the cover open / close detection switch 36, and input via the cover open / close input circuit 58. An off signal (open signal) and an on signal (close signal) are captured.
The setting signal (sensitivity setting signal, sensitivity non-setting signal) of the dip switch input via the is taken.

Next, at step S2, the distance selection switch 3
It is determined whether or not 7 is in the sensitivity setting state. That is,
The sensitivity setting state determination unit 75 determines whether the sensitivity has been set. If the sensitivity has not been set, the process proceeds to step S3. If the sensitivity has been set, the process proceeds to step S8.
Proceed to. In step S3, the cover open / close detection switch 36
Is turned on. That is, the cover 2
Is determined by the cover open / closed state determination unit 76, and if the cover 2 is closed, step S
Proceed to 4.

When it is detected by the distance selection switch 37 that the cover 2 is closed in a state where the sensitivity setting has not been set, it is determined that the sensitivity setting has been forgotten, and a failure signal is immediately output in step S4. . The failure signal output from the failure signal output unit 77 is transmitted to the receiver 46 and causes the failure indicator 35 to blink. This informs the person in charge that the sensitivity setting has been forgotten.

If the cover 2 has been opened in step S3, it is determined in step S5 whether or not a predetermined time T2, for example, 2 hours, has elapsed.
Outputs a fault signal. The predetermined time T2 sets a time required for optical axis adjustment. That is, when it is detected that the cover 2 has been opened for 2 hours or more in a state where the sensitivity has not been set, the optical axis has been adjusted but the sensitivity setting or the cover 2 has been forgotten to be closed, or only the power supply is connected. After that, the failure signal output unit 77
Outputs a failure signal to the receiver 46 and causes the failure indicator light 35 to blink. The failure signal informs the person in charge of the occurrence of the above-described failure.

When two hours have not elapsed in step S5, that is, when the sensitivity is not set, the cover 2
If is opened, the process proceeds to step S7 and enters the adjustment mode. In step S7, the monitor indicator lamp LE
D38A to 38F blink, the optical axis confirmation lamp 33 blinks, and the monitoring cycle (light emission cycle) is changed to a short cycle.

Next, in a state where the sensitivity is set, it is determined in step S8 whether or not the cover open / close detection switch 36 is off. If the cover 2 is open, the process proceeds to step S9.
Then, it is determined whether or not a predetermined time T1, for example, 5 minutes has elapsed, and if 5 minutes have elapsed, a failure signal is output in step S10. That is, when it is detected that the cover 2 has been opened for 5 minutes or more in a state where the sensitivity setting has been set, the sensitivity has been set, the cover 2 has been forgotten to be closed, or a later shock such as a ball When it is determined that the cover 2 has come off due to a hit or the like, the fault signal output unit 77 outputs a fault signal to the receiver 46, and the fault indicator 35
Flashes. Thereby, the person in charge is notified that the above-mentioned trouble has occurred. The predetermined time T1 is a time from when the sensitivity is set to when the cover 2 is closed.

When the sensitivity setting is set and the cover 2 is closed, it is determined that the adjustment of the optical axis and the received light amount has been completed, and the flag indicating the registration of the initial value is set to 0 (initial value) in step S11. It is determined whether or not the value is not registered. If the initial value is not registered, the received light output at that time is registered as an initial value in step S12, and the initial value and the distance selection switch 37 are registered in step S13. The threshold (fire level) is calculated from the set sensitivity, the initial value is registered, and the flag is set to 1 in step S14 to store that the initial value is registered. If it is determined in step S11 that the initial value has already been registered, the fire monitoring is continuously performed at the already registered threshold value.

In this embodiment, the fault signal output unit 77
Indicates that (1) the cover 2 is in a state where the sensitivity setting is not set.
(2) When it is detected that the cover 2 has been opened for a predetermined time T1 (for example, 5 minutes) with the sensitivity setting set, when it is detected that the cover 2 has been closed (when the sensitivity setting is forgotten). (When the sensitivity is set but the cover 2 is forgotten to be closed, or when the cover 2 comes off due to some shock such as a ball hit later), (3) If the cover 2 is not set and the sensitivity is not set When it is detected that it has been opened for a predetermined time T2 (for example, 2 hours) or more (when the optical axis is adjusted but the sensitivity setting or closing of the cover 2 is forgotten, only the power supply is connected, and nothing is done afterwards) ,
The failure signal is output to the receiver 46 and the failure indicator light 35 is made to blink, so that the failure can be notified to a person in charge of the above-mentioned failure, and the person in charge cannot monitor normally. The state can be grasped reliably.

[0050]

As described above, according to the present invention, when the cover is closed with the sensitivity setting forgotten, and the sensitivity is set but the cover is forgotten to close, the optical axis is adjusted but the sensitivity is set. If you forget to close the cover or cover, a fault signal is output to the receiver and the fault indicator light flashes, so that the occurrence of a fault can be notified.
It is possible to surely grasp that the state cannot be monitored normally.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an exploded perspective view of a light receiver showing one embodiment of the present invention.

FIG. 3 is a front view of a light receiver.

FIG. 4 is a side view of a light receiver.

FIG. 5 is a block diagram of a light receiver and a light transmitter.

FIG. 6 is a flowchart illustrating an operation.

FIG. 7 shows a conventional example.

FIG. 8 is a side view showing another conventional example.

FIG. 9 is a front view showing another conventional example.

[Explanation of symbols]

1: Receiver 2: Cover 2A: Window 3: Main body 4: Cover fixing wire 5: Fixing bracket 6: Cover fixing bracket 7: Lens holder 7A: Locking piece 7B, 7C: Aiming hole 7D: Reflection mirror 7E: Lens 8 : Mounting plate 8A: Locking piece 9: Base 9A: Fitting hole 9B: Shaft hole 9C: Locking hole 9D, 9E: Flange section 10: Shield case 11: Printed circuit board 12: Power supply board 13: Insulating sheet for light receiving board 14: Circuit cover 15: Support member 15A: Shaft hole 15B, 15C, 15E: Locking hole 15D: Fitting hole 16, 23: Coil spring 17: Separator 17A: Hole 17B: Recess 17C: Shaft hole 18: Mounting screw 19A , 19B: Receiving screw 20A, 20B: Adjusting screw 21, 22, 26, 27: Screw 24: Light receiving board 25: Light receiving shield case 28, 29: Light receiving amount Adjusting knobs 30, 31: Optical axis adjusting knob 32: Terminal nameplate 33, 56: Optical axis confirmation light 34: Fire indicator light 35: Fault indicator light 36, 70: Cover open / close detection switch 37: Distance selection switch 38A to 38F: LED 39: insertion terminal section 40, 41: light transmitter control line 42: light transmitter 43: fire signal line 44: common line 45: fault signal line 46: receiver 47: constant voltage current limiting circuit 48: light emission control circuit 49 , 64: diode 50: control unit 51: light emission control detection circuit 52: light emission drive circuit 53: light emission element 54: light reception element 55: optical axis confirmation lamp drive circuit 57: sensitivity input circuit 58: cover opening / closing input circuit 59: oscillation circuit 60: 5V constant voltage circuit 61: optical axis confirmation light control circuit 62: failure signal output cutoff circuit 63: failure signal output circuit 65: photoelectric conversion circuit 66: amplification circuit 6 : A / D converter 69: Drive table 71: Fire signal detection circuit 72: Variable resistance 73: Peak hold circuit 74: Received light quantity input circuit 75: Sensitivity setting state discriminator (sensitivity setting state discriminating means) 76: Cover open / close state Judging section (cover open / closed state judging means) 77: fault signal output section (fault signal output means) 78: RAM

Claims (1)

(57) [Claims] 1. A photoelectric separation type smoke detector for separately arranging a light transmitter having a light emitting element and a light receiver having a light receiving element and detecting attenuation of light caused by smoke therebetween. A cover open / closed state determination means for determining whether the cover is open / closed by turning on / off a cover open / close detection switch for detecting opening / closing of a front cover which is opened / closed for adjusting an optical axis and setting a sensitivity, according to a monitoring distance. A sensitivity setting state determining means for determining a setting state of a distance selection switch for setting a sensitivity, and when it is detected that the cover is closed in a state where the sensitivity setting is not set, or the sensitivity setting is set. When it is detected that the cover has been opened for a predetermined time T1 or more in a state in which the cover is opened, or when the cover has been opened for a predetermined time T2 or more in a state where the sensitivity is not set. When it detects that
A photoelectric type smoke detector characterized by comprising a failure signal output means for outputting a failure signal to a receiver.