JP2019096270A - Smoke detector and optical axis alignment method for the same - Google Patents

Abstract

To provide a smoke detector allowing easy optical axis adjustment.SOLUTION: A smoke detector is a photoelectric separation sensor comprising a light emitter including a light-emitting element and a light receiver 10 including a light receiving element, which are arranged separately, and sensing fire by detecting attenuation of light caused by smoke therebetween. The light emitter comprises: an optical bench on which the light-emitting element is mounted and is swingably supported to a housing; and a piezoelectric actuator interposed between the housing and the optical bench and changing an inclination of the optical bench to the housing. The light receiver 10 comprises: an optical bench 12 on which the light receiving element 13 is mounted and is swingably supported to a housing 11; and a piezoelectric actuator 20 interposed between the housing 11 and the optical bench 12 and changing an inclination of the optical bench 12 to the housing 11. The light emitter and/or the piezoelectric actuator 20 of the light receiver 10 is controlled based on an amount of light received by the light receiver 10 to perform optical axis alignment between the light emitter and the light receiver 10.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a smoke sensor in which a light emitter and a light receiver are disposed in a monitoring space.

  Conventionally, the photoelectric separation type sensor faces the light emitter containing the light emitting element and the light receiver containing the light receiving element with a monitoring distance of usually 5 to 100 m at a high place (usually 10 to 15 m above the ground) Deploy. If there is smoke between the light emitter and the light receiver, the photoelectric separation sensor senses the light decay to detect fire. In addition, the integrated sensor has a light emitting and receiving device in which a light emitting device and a light receiving device are accommodated in one case, and a reflecting plate is disposed to face in a light receiving and emitting direction of the light receiving and emitting device. If smoke is present between the light emitter / receiver and the reflector, the integrated sensor also senses light attenuation to detect a fire, as does the photoelectric sensor. Therefore, in order for both the photoelectric separation type sensor and the integrated type sensor to operate properly, it is necessary that the optical axes of the light emitter and the light receiver coincide with each other.

  Patent Document 1 discloses a photoelectric separation type sensor capable of adjusting an optical axis using a collimation hole. In the photoelectric separation type sensor described in this document, first, the horizontal angle adjustment male screw and the vertical angle adjustment male screw are checked while the position of the light receiver is confirmed using the collimation hole, the observation hole and the reflecting mirror. Make coarse adjustments to the horizontal and vertical angles of the optical bench. Subsequently, while confirming the light reception output level using a voltmeter or the like, the horizontal angle and the vertical angle of the optical bench are finely adjusted so as to obtain a predetermined output.

JP 2014-59784

  In the smoke sensor of the type that senses smoke by light attenuation, various optical axis adjustment methods have been proposed, including Patent Document 1 mentioned above. However, in the conventional method, it is necessary to perform the optical axis adjustment operation at a high place, which is dangerous.

  Then, an object of this invention is to provide the smoke detector which can perform adjustment of an optical axis easily.

  A smoke sensor according to the present invention is a smoke sensor that has a light emitter having a light emitting element and a light receiver having a light receiving element, and detects a decay of light due to smoke in a monitoring space to detect a fire, The light emitting device is mounted between the optical bench which mounts the light emitting element and is swingably supported with respect to a housing, the housing and the optical bench, and the tilt of the optical bench with respect to the housing And a light receiving element mounted between the light receiving element and an optical bench supported swingably with respect to the housing, and interposed between the housing and the optical bench A piezoelectric actuator for changing the tilt of the optical bench with respect to the housing, and controlling the piezoelectric actuator of the light emitter and / or the light receiver based on the amount of light received by the light receiver to control the light emitter The optical axis alignment of the light receiver is performed.

  By controlling the piezoelectric actuator interposed between the movable optical bench and the housing based on the amount of received light according to the amount of received light as described above, the worker can automatically perform the operation without taking a manual operation at a high place. Alignment can be performed.

  In the smoke detector of the present invention, the light emitter and the light receiver may be disposed to face each other across at least a part of the monitoring space. Thus, in the separate type smoke sensor in which the light emitter and the light receiver are disposed opposite to each other, optical axis alignment can be appropriately performed.

  In the smoke detector according to the present invention, the light emitter and the light receiver may be configured as one light receiver / emitter, and may have a reflecting plate facing the light emitter / receiver. At that time, instead of the optical bench supporting the light emitting element and the light receiving element, a common optical bench supporting the light emitting element and the light receiving element is provided, and between the housing and the common optical bench And a piezoelectric actuator that changes the tilt of the optical bench with respect to the housing. Thus, even in the reflection type smoke sensor in which the light emitter and the light receiver are integrated, the optical axis alignment can be appropriately performed.

  In the smoke sensor of the present invention, the light emitter and / or the light receiver may be provided with a hinge that swingably supports the optical bench.

  With this configuration, the optical bench can be swingably supported about the pivot axis of the hinge.

  In the smoke sensor according to the present invention, the light emitter and / or the light receiver may include a spherical portion pivotally supporting the optical bench, and an elastic member biasing the optical bench with respect to the spherical portion. You may have. Further, the light emitter and / or the light receiver may be formed in a shape corresponding to the first spherical surface portion provided on the optical bench, and the housing in the shape corresponding to the first spherical surface portion, and the first spherical surface And a second spherical portion in surface contact with the portion.

  With these configurations, the optical bench can be swung in any direction, and the optical bench can be tilted in a desired direction by the arrangement of the piezoelectric actuator.

  The smoke sensor according to the present invention includes a control unit that controls the orientation of the light axis of the light emitter and / or the light receiver, and the control unit is configured to control the piezoelectric of the light emitter and / or the light receiver at the time of initialization. The light axis alignment of the light emitter and the light receiver may be performed based on the amount of light received when the value of the actuator is displaced.

  As described above, at the time of initial setting before operating the smoke sensor, the optical axis alignment is performed based on the amount of light received when the piezoelectric actuator is displaced, whereby the initial setting operation can be easily performed. Note that “at the time of initial setting” is typically when the smoke detector is first installed, but also when the worker shuts down the smoke detector and resets it when something goes wrong. included.

  The smoke sensor according to the present invention includes a control unit that controls the direction of the light axis of the light emitter and / or the light receiver, and when the light reception amount satisfies a predetermined condition during operation, the control unit Fire detection may be performed intermittently while performing optical axis alignment of the light emitter and the light receiver.

  As described above, when the light reception amount satisfies the predetermined condition at the time of operation and the shift of the optical axis is detected, the optical axis alignment can be performed automatically. In addition, by performing fire detection intermittently while performing optical axis alignment, fire detection is performed even while optical axis alignment between the light emitter and the light receiver is performed, so optical axis alignment can be performed safely. It can be carried out.

  In the smoke sensor of the present invention, the predetermined condition may be that the amount of received light is higher than a fire detection threshold and is lower than a first threshold for a predetermined time.

  As described above, when the state of being higher than the threshold for detecting a fire and being lower than the first threshold continues for a predetermined time, it is considered that the optical axis of the light emitter and the light receiver deviates and the light receiving amount decreases. It is desirable to start optical alignment.

  The smoke sensor of the present invention may further include a notification unit that notifies that the amount of light received after optical axis alignment does not reach the second threshold.

  If the amount of received light does not reach the second threshold even if the optical axis alignment is performed and the optical axis alignment can not be performed sufficiently, the operator is notified of the fact that automatic adjustment can not be performed, and the operator can adjust the optical axis alignment. Can be done.

  The light axis alignment method of the smoke sensor according to the present invention arranges the light emitter capable of controlling the light emission direction and the light receiver capable of controlling the light reception direction toward the monitoring space, and detects the light attenuation by the smoke to detect a fire. Determining the amount of light received by the light receiver satisfying a predetermined condition, and determining that the amount of light received by the light receiver satisfies a predetermined condition And a step of intermittently detecting the fire based on the amount of light received by the light receiver while aligning the light axes of the light emitter and the light receiver.

  As described above, when the light reception amount satisfies the predetermined condition at the time of operation and the shift of the optical axis is detected, the optical axis alignment can be performed automatically. In addition, by performing fire detection intermittently while performing optical axis alignment, fire detection is performed even while optical axis alignment between the light emitter and the light receiver is performed, so optical axis alignment can be performed safely. It can be carried out.

  In the optical axis alignment method of a smoke sensor according to the present invention, the predetermined condition is that the amount of received light is higher than a fire detection threshold and is lower than a first threshold for a predetermined time. Good.

  As described above, when the state where the fire detection threshold is higher than the fire detection threshold and is lower than the first threshold continues for a predetermined time, it is conceivable that the light axis is shifted and the light reception amount is decreased. It is desirable to start.

  The optical axis alignment method of the smoke sensor according to the present invention may further include the step of notifying that the light reception amount after optical axis alignment does not reach the second threshold.

  If the amount of received light does not reach the second threshold even if the optical axis alignment is performed and the optical axis alignment can not be performed sufficiently, the operator is notified of the fact that automatic adjustment can not be performed, and the operator can adjust the optical axis alignment. Can be done.

  The present invention controls the piezoelectric actuator interposed between the pivotable optical bench and the housing based on the amount of received light according to the amount of received light, so that the worker does not have to do manual work at high places Optical axis alignment can be performed automatically.

It is a figure shown about the whole structure of the photoelectric type separation type sensor of embodiment. It is sectional drawing which shows the structure of the light receiver of 1st Embodiment. It is a figure explaining support of an optical bench of a 1st embodiment. It is a figure explaining judgment of a photoelectric type separation type sensor. It is sectional drawing which shows the structure of the light receiver of 2nd Embodiment. It is a figure explaining support of the optical bench of a 2nd embodiment. It is sectional drawing which shows the structure of the light receiver of 3rd Embodiment. It is a figure explaining support of the optical bench of a 3rd embodiment. It is a flowchart which shows the operation | movement of optical axis alignment of a photoelectric type separation type sensor. It is a flowchart which shows the operation | movement at the time of operation | use of a photoelectric type separation type sensor.

Hereinafter, a smoke sensor according to an embodiment of the present invention will be described with reference to the drawings. In the embodiment, the photoelectric separation type sensor is mainly described, but an integrated smoke sensor is also included in the scope of the present invention.
First Embodiment
FIG. 1 is a diagram showing an entire configuration of the photoelectric separation type sensor 1. The photoelectric separation type sensor 1 is configured by opposingly arranging the light emitter 40 and the light receiver 10 in the monitoring space. The light emitting device 40 and the light receiving device 10 have almost the same configuration except for the light emitting element, the light receiving element, and the related circuit. Therefore, in the following description, the light receiving device 10 will be described as an example.

  FIG. 2 is a cross-sectional view showing the configuration of the light receiver 10 according to the first embodiment. The light receiver 10 has a housing 11 in which a window 14 for taking in light emitted from the light emitter 40 is formed, and has a light receiving element 13 mounted on an optical bench 12 inside the housing 11 It is The light receiving element 13 has a function of converting the light received on the light receiving surface into an electric signal corresponding to the amount of light received, and inputs the converted electric signal into an electric circuit (not shown) formed on the optical bench 12 The circuit detects a fire.

  The light receiving surface of the light receiving element 13 is directed toward the window 14 of the housing 11, and a lens 15 is provided between the light receiving element 13 and the window 14. The lens 15 has a role of concentrating the light incident from the window 14 on the light receiving surface.

  The optical bench 12 is swingably supported on the inner wall of the housing 11. Specifically, the hinge 16 is attached to one side of the optical bench 12. The piezoelectric actuator 20 is interposed between the optical bench 12 and the housing 11, and the distance between the optical bench 12 and the housing 11 is secured by the height of the piezoelectric actuator 20. Near the side of the optical bench 12 opposite to the hinge 16, a support shaft 17 penetrating the optical bench 12 is provided. A spring 19 as an elastic member is disposed between the head 18 of the support shaft 17 and the optical bench 12, and the optical bench 12 is biased toward the housing 11. A washer or the like may be provided between the spring 19 and the optical bench 12 so that the spring 19 presses the optical bench 12 reliably.

  As shown in FIG. 3, the hinge 16, the piezoelectric actuator 20, and the support shaft 17 are arranged in a substantially straight line. Since the piezoelectric actuator 20 is interposed between the optical bench 12 and the housing 11, when the optical bench 12 is urged toward the housing 11 by the spring 19, the distance corresponding to the height of the piezoelectric actuator 20 The optical bench 12 is fixed while holding the Then, when a voltage is applied to the piezoelectric actuator 20, the piezoelectric actuator 20 expands and contracts according to the applied voltage to change the tilt of the optical bench 12, whereby the optical axis of the light receiving element 13 can be changed.

  A lead wire 21 connected to the light emitter 40 is connected to the optical bench 12. The light receiving device 10 and the light emitting device 40 are connected by the lead wire 21 so that the light receiving device 10 and the light emitting device 40 cooperate with each other to perform fire detection and optical axis alignment. Moreover, the lead wire 21 is connected with the monitoring apparatus which is not shown in figure, and has a function which communicates a fire signal and a fault signal to a monitoring apparatus.

  The configuration of the light receiver 10 has been described above with reference to FIGS. 2 and 3. However, the light emitter 40 includes a light emitting element in place of the light receiving element 13 and an electric circuit for controlling the light emitting element. The rest is basically the same as the configuration of the light receiver 10.

  The photoelectric separated sensor 1 includes a control unit that controls the light receiver 10 and the light emitter 40. The control unit may be provided in any of the light receiver 10 and the light emitter 40. FIG. 2 shows an example in which the control unit 22 is provided in the light receiver 10. When the control unit 22 is provided in the light receiver 10, a control signal is transmitted to the light emitter 40 through the lead wire 21, and the light emitter 40 emits light at a predetermined angle and at a predetermined timing based on the control signal.

  The control unit 22 has a function of detecting a fire, a function of performing optical axis alignment, and a function of detecting a fault. FIG. 4 is a diagram showing what kind of determination the control unit 22 makes based on the amount of light received by the light receiving element 13. The photoelectric separation type sensor 1 stores the light receiving amount at the time of initial setting as an initial setting value, and determines the light receiving amount with reference to the initial setting value. While the light receiving amount in the light receiving element 13 holds 80% or more of the initial set value, it is determined that the light receiving element is normal. When the amount of light received by the light receiving element 13 falls below 80% but holds 50% or more, when this state continues for a predetermined time, it is determined that the optical axis has deviated, and optical axis alignment is autonomously started Do. If the amount of light received by the light receiving element 13 falls below 50%, it is determined that a fire has occurred. However, if the amount of light received by the light receiving element 13 does not go through the state of 50% to 10% and the amount of light received suddenly falls below 10%, it is determined that a fault occurs in the photoelectric separation type sensor 1 . In addition, the threshold value (80%, 50%, 10%) of the determination demonstrated here is an illustration, Comprising: Each threshold value can be set appropriately. The control unit 22 automatically performs the optical axis alignment in cooperation with the light receiver 10 and the light emitter 40. This operation will be described later.

Second Embodiment
FIG. 5 is a view showing the configuration of the light receiver 10 of the photoelectric separated sensor according to the second embodiment, and FIG. 6 is a view showing the support of the optical bench 12. The basic configuration of the photoelectric separated sensor of the second embodiment is the same as that of the photoelectric separated sensor 1 of the first embodiment, but the method of supporting the optical bench 12 is It is different.

  In the second embodiment, the optical bench 12 is supported by the optical bench 12 by the support shafts 17, 23, 25 and two piezoelectric actuators 20 interposed between the optical bench 12 and the housing 11. . The support shaft 17 penetrates the optical bench 12. A spring 19 is disposed between the head 18 of the support shaft 17 and the optical bench 12, and the optical bench 12 is biased toward the housing 11.

  The support shaft 23 has a spherical head 24. A female screw is formed on the head 24, and a support shaft 25 screwed with the female screw penetrates the optical bench 12. A spring 27 as an elastic member is disposed between the head 26 of the support shaft 25 and the optical bench 12, and the optical bench 12 is biased by the head 24 of the support shaft 23.

  The spring 27 provided on the support shaft 25 has a larger spring constant than the spring 19 provided on the support shaft 17, and the optical bench 12 is pressed against the head 24 of the support shaft 23 by the spring 27. Since the head 24 of the support shaft 23 is spherical, the optical bench 12 pivots about the head 24 of the support shaft 23. A washer or the like may be provided between the springs 19 and 27 and the optical bench 12 so that the springs 19 and 27 reliably push the optical bench 12.

  As shown in FIG. 6, the two support shafts 17 and 23 are provided on the diagonal of the optical bench 12. In addition, in the vicinity of two adjacent sides of the optical bench 12, the piezoelectric actuator 20 is interposed between the housing 11 and the optical bench 12, and the force by which the optical bench 12 is biased toward the housing 11 by the spring 19 Against which the optical bench 12 is supported. By applying a voltage to the two piezoelectric actuators 20, the tilt of the optical bench 12 can be changed.

  The configuration of the light receiver 10 has been described above with reference to FIGS. 5 and 6, but the light emitter 40 includes a light emitting element in place of the light receiving element 13 and an electric circuit for controlling the light emitting element. The rest is basically the same as the configuration of the light receiver 10.

Third Embodiment
FIG. 7 is a view showing the configuration of the light receiver 10 of the photoelectric separated sensor according to the third embodiment, and FIG. 8 is a view showing the support of the optical bench 12. The basic configuration of the photoelectric separated sensor of the third embodiment is the same as that of the photoelectric separated sensor 1 of the first embodiment, but the method of supporting the optical bench 12 is the same. It is different.

  In the third embodiment, at the central position of the optical bench 12, a first spherical surface portion 28 projecting toward the housing 11 is formed. The first spherical surface portion 28 is formed by bending the optical bench 12 toward the housing 11 and, as shown in FIG. 7, has a hemispherical shape with an even curvature over the entire surface.

  On the other hand, the casing 11 is provided with a rising portion 29 projecting toward the optical bench 12 side. A second spherical portion 30 is formed at an end of the rising portion 29 on the side of the optical bench 12. The second spherical portion 30 has a shape corresponding to the first spherical portion 28, that is, a spherical shape that protrudes toward the housing 11 at the end of the rising portion 29 on the side of the optical bench 12. It is assumed that the curvature of the spherical portion 28 of 1 is substantially the same. Then, as shown in FIG. 7, the first spherical surface portion 28 and the second spherical surface portion 30 are disposed adjacent to each other, and the second spherical surface portion 28 is disposed on the side surface of the housing 11 side. The optical bench 12 and the housing 11 are linked by the contact of the side surface of the spherical portion 30 on the side of the optical bench 12 and the surface contact between the first spherical portion 28 and the second spherical face 30.

  In addition, two piezoelectric actuators 20 are interposed between the housing 11 and the optical bench 12. That is, the optical bench 12 is supported by surface contact of the two piezoelectric actuators 20 and the first spherical portion 28 and the rising portion 29 described above. As shown in FIG. 8, the two actuators are located in two directions orthogonal to each other about the first spherical surface portion 28. Thus, by applying a voltage to the two piezoelectric actuators 20, the tilt of the optical bench 12 can be changed along the two axes.

  As mentioned above, although the structure of the light receiver 10 was demonstrated with reference to FIG.7 and FIG.8, the light emitter 40 is replaced with the light receiving element 13, and the point provided with the light emitting element, The electric circuit which controls the said light emitting element The rest is basically the same as the configuration of the light receiver 10.

(Operation of optical axis alignment)
Each of the photoelectric separated sensors according to the first to third embodiments described above has a configuration in which the tilt of the optical bench 12 can be changed by the piezoelectric actuator 20, and the light receiving element 13 receives light. Automatically adjust the optical axis based on the quantity.

  When the worker installs the photoelectric separation type sensor in the monitoring area and then starts the optical axis alignment operation by pressing the optical axis alignment button or the like, the photoelectric type separation sensor detects the amount of light received by the light receiver 10 Align the optical axis based on Basically, the photoelectric separation type sensor determines the optical axis direction of the light receiver 10 and the light emitter 40 such that the amount of light received by the light receiver 10 becomes maximum. Specifically, the set value of the piezoelectric actuator 20 is displaced by predetermined steps, the light axis of the light receiver 10 and the light axis of the light emitter 40 are gradually shifted to measure the light reception amount, and the light reception amount is maximized. The set value of the piezoelectric actuator 20 is obtained.

  Hereinafter, with reference to FIG. 9, the operation of the optical axis alignment of the photoelectric separated sensor of the present embodiment will be specifically described. First, the set value of the piezoelectric actuator 20 of the light receiver 10 is set to the minimum (S10), and in that state, the light emitter 40 emits light (S11) and the light receiver 10 receives light (S12). The light receiver 10 stores the amount of light received at this time. Next, it is determined whether the set value of the piezoelectric actuator 20 of the light receiver 10 is the maximum value (S13). If the set value of the piezoelectric actuator 20 is not the maximum value (NO in S13), the piezoelectric actuator 20 is The setting value of is increased by one step (S14), and again the light emitted by the light emitter 30 is received by the light receiver 10 (S12), and the amount of light received at this time is stored. Likewise, the set value of the piezoelectric actuator 20 is gradually increased (S14), and the operation of receiving light by the light receiver 10 is repeated until the set value of the piezoelectric actuator 20 reaches the maximum value (YES in S13). .

  Based on the amount of light received while changing the set value of the piezoelectric actuator 20 from the minimum value to the maximum value, the value of the piezoelectric actuator 20 of the light receiver 10 at which the amount of received light becomes maximum is determined (S15). Then, the light receiver 10 fixes the angle of the optical bench 12 using the determined value, that is, fixes the optical axis direction of the light receiver 10.

  Next, the same adjustment is performed for the light emitter 40. That is, the setting value of the piezoelectric actuator 20 of the light emitter 40 is set to the minimum (S16), and in that state, the light emitter 40 emits light (S17) and the light receiver 10 receives light (S18). The light receiver 10 stores the amount of light received at this time. Next, it is determined whether the set value of the piezoelectric actuator 20 of the light emitter 40 is the maximum value (S19). If the set value of the piezoelectric actuator 20 is not the maximum value (NO in S19), the piezoelectric actuator 20 is The set value is increased by one step (S20), and the light is emitted again by the light emitter 40 (S17), received by the light receiver 10 (S18), and the amount of light received at this time is stored. Similarly, the setting value of the piezoelectric actuator 20 is gradually increased (S20), and the operation of receiving light by the light receiver 10 is repeated until the setting value of the piezoelectric actuator 20 reaches the maximum value (YES in S19). .

  Based on the amount of light received while changing the setting value from the minimum value to the maximum value from the minimum value to the maximum value of the piezoelectric actuator 20, the value of the piezoelectric actuator 20 of the light emitter 40 for which the light reception amount is maximum is determined (S21). Then, the light emitter 40 fixes the angle of the optical bench 12 using the determined value, that is, fixes the optical axis direction of the light emitter 40.

  As described above, the photoelectric separation type sensor according to the present embodiment sweeps the piezoelectric actuator 20 of the light receiver 10 and the light emitter 40 to obtain the piezoelectricity of the light receiver 10 and the light emitter 40 that maximizes the amount of light received. The optical axis alignment is automatically performed by a method of determining the setting value of the actuator 20.

  In the above-described embodiment, although the example in which the optical axis of the light emitter 40 is determined after the optical axis of the light receiver 10 is determined is described, the optical axis of the light emitter 40 may be determined first. Good. It is desirable to determine which one of the light receiver 10 and the light emitter 40 has the highest directivity first. Further, in the above-described embodiment, the setting value of the piezoelectric actuator 20 is displaced from the low side to the high side, but it may of course be displaced from the high side to the low side.

  Further, in the above embodiment, a one-dimensional adjustment method has been described as an example, but as in the second embodiment and the third embodiment, the optical bench 12 is used. When oscillating with respect to two axes, two-dimensional adjustment is performed. That is, the light reception amount is measured for all combinations of the values (x, y) of the two piezoelectric actuators 20, and the combination of the set values of (x, y) at which the light reception amount is maximum is determined.

  In the embodiment described above, the setting value of the piezoelectric actuator 20 is changed one step at a time from the minimum value to the maximum value, but at first, the setting value is roughly shaken to increase the light receiving amount. The setting value may be finely shaken in the vicinity of the angle. As a result, the setting value at which the amount of received light becomes maximum can be obtained quickly.

(Operation of photoelectric separated sensor)
FIG. 10 is a flow chart showing the operation of the photoelectric separated sensor during operation. Since the photoelectric separation type sensor makes the determination shown in FIG. 4 according to the amount of light received, it makes the determination to realize this.

  The photoelectric separation type sensor receives the light emitted by the light emitter 40 by the light receiver 10 (S30), and determines whether the light reception amount is 50% or less of the initial set value (S31). If the light reception amount is 50% or less (YES in S31), the photoelectric separation sensor 1 determines whether the light reception amount is 10% or less of the initial set value (S32). If the light receiving amount is not 10% or less of the initial setting value (NO in S32), that is, if the light receiving amount is 10% to 50% of the initial setting value, it is determined that a fire has occurred (S33). Output a fire signal. If the light reception amount is 10% or less of the initial set value (YES in S32), the photoelectric separated sensor 1 determines that a fault has occurred (S34), and outputs a fault occurrence signal to the outside.

  In the case of a fire, since the light path between the light emitter 40 and the light receiver 10 is blocked by smoke and the light is attenuated, the amount of light received does not suddenly fall below 10%, and the amount of light received is 10% to 50%. The decrease in the amount of received light can be captured when it becomes%. The amount of light received suddenly decreases to 10% or less, for example, when an impact is applied to the light receiver 10 or the light emitter 40 and the optical axis between the light receiver 10 and the light emitter 40 is largely deviated, Since it is considered to be a failure, it is judged not to be a fire but a failure.

  If the light reception amount is not 50% or less (NO in S31), the photoelectric separation sensor 1 determines whether the light reception amount is 80% or less (S35). If the light reception amount is not 80% or less (NO in S35), that is, if the light reception amount exceeds 80%, the timer is reset (S36), and the light emitted by the light emitter 40 is received again. A step of receiving light at 10 is performed (S30). The step of receiving light emitted by the light emitter 40 may be performed at predetermined intervals (for example, every 3 seconds).

  If it is determined in step S35 that the light reception amount is 80% or less (YES in S35), the timer is started if the timer has not been started (S37). This timer is a timer that counts a duration to detect an optical axis shift and start optical axis alignment when a time when the light reception amount is 50% to 80% continues for a predetermined time or more.

  The photoelectric separated sensor determines whether the timer value has become equal to or greater than a predetermined threshold (for example, 24 hours) (S38). If the timer value does not reach the predetermined threshold (NO in S38), the step of receiving the light emitted by the light emitter 40 by the light receiver 10 is performed again (S30).

  If the timer value becomes equal to or greater than the predetermined threshold (YES in S38), the photoelectric separation sensor performs optical axis alignment (S39). The optical axis alignment is basically performed in accordance with the flow described in FIG. 9, except that the fire detection needs to be continued during the operation of the photoelectric separation type sensor. Specifically, in the flow shown in FIG. 9, the optical axis of the light emitter 40 and the light receiver 10 is aligned before the measurement of the light reception amount by increasing the set value of the piezoelectric actuator 20 (S14, S20). The light receiving amount is measured by returning to the angle before the execution, and it is determined whether a fire has occurred (that is, whether the light receiving amount is 10% to 50% or less).

  For example, if the measurement of the light reception amount is performed in 20 steps for each of the X axis and the Y axis, 20 × 20 = 400 conditions with the light receiver 10 alone and 800 conditions with the light emitter 40 included. It is necessary to measure the light reception amount, and the time required for this is 40 minutes even if it is 3 seconds per condition. Therefore, if the fire detection is not performed at all while performing the optical axis alignment, the occurrence of the fire may be overlooked. As in the present embodiment, by performing fire detection intermittently while performing the optical axis alignment, it is possible to safely perform the optical axis alignment without fear of occurrence of a fire being overlooked.

  When the optical axis alignment is completed, the photoelectric separation type sensor 1 determines whether the light reception amount after optical axis alignment is 60% or more (S40). If the light reception amount is less than 60% despite the optical axis alignment (NO in S40), it is determined that a fault has occurred (S34), and a fault signal is output to the outside. Here, the fault signal output to the outside corresponds to a signal notifying that effect when the light reception amount after optical axis alignment does not reach a predetermined threshold. If the light reception amount is 60% or more (YES in S40), the light reception amount after optical axis alignment is set as the reference light reception amount (S41), and the process returns to the beginning of the flow.

  In the operation described here, it is first determined whether there is a possibility of fire occurrence depending on whether the light receiving amount is 50% or less (S31), and if the light receiving amount is not 50% or less (S31) NO) It is judged whether or not the optical axis alignment is performed (S35), but the judgment as to whether or not the optical axis alignment is performed may be performed separately from the judgment as to whether or not the received light amount is 50% or less . In this case, the condition as to whether or not the optical axis alignment is performed is that the state in which the amount of received light falls below a threshold (for example, 80%) higher than the threshold for sensing a fire continues for a predetermined time.

  The configuration and operation of the photoelectric separated sensor according to the embodiment have been described above. The photoelectric type separation type sensor according to the present embodiment has a configuration in which the light receiving element 13 and the light emitting element are mounted on an optical bench 12 that can swing relative to the housing 11 and the angle of the optical bench 12 is changed by the piezoelectric actuator 20 Thus, the photoelectric separation sensor can control the piezoelectric actuator 20 based on the amount of light received by the light receiving element 13 and automatically perform optical axis alignment. Thereby, the adjustment at the time of construction of a photoelectric type separation type sensor can be saved. In addition, the photoelectric separated sensor according to the embodiment detects that the optical axis has shifted based on the amount of light received during operation, and performs adjustment automatically, so that an appropriate monitoring state can be maintained.

  In the photoelectric separated sensor 1 according to the first embodiment, an optical bench 12 on which a light receiving element 13 and a light emitting element are mounted is swingably supported by a hinge 16, and its tilt is changed by a piezoelectric actuator 20. Therefore, the optical bench 12 can be rocked along the pivot axis of the hinge 16.

  In the photoelectric separated sensors according to the second and third embodiments, since the tilt of the optical bench 12 is adjusted by the two piezoelectric actuators 20, it can be oscillated along two axes. And appropriate alignment can be performed.

  Although the smoke detector of the present invention has been described in detail by way of the embodiments, the present invention is not limited to the above-described embodiments.

  In the above embodiment, the configuration in which the optical bench is supported by the hinge and the support shaft is described as an example, but the optical bench may be supported only by the piezoelectric actuator. For example, three or four or more piezoelectric actuators may be adhesively bonded to the optical bench to support the optical bench. This configuration can support the optical bench and change its tilt.

  In addition, an optical bench which can be rocked by arbitrarily combining the configurations (the hinge 16, the springs 19 and 27, the first spherical surface portion 28 and the rising portion 29) described in the first to third embodiments. May be configured.

  In the embodiment described above, the optical axis alignment has been described by taking the photoelectric separated sensor as an example, but also in the case of the reflection type smoke sensor, the configuration of the optical axis alignment is the same as in the above embodiment. It can be realized. The reflection type smoke sensor is configured to include a light emitting and receiving device having a light emitting device and a light receiving device, and a reflecting plate disposed to face the light emitting and receiving device. There are two types of light emitting and receiving devices: a type in which the light emitting device and light receiving device are mounted on the same optical bench, and a type in which the light emitting device and light receiving device are mounted on different optical benches. In any type, the optical bench is supported so as to be able to swing relative to the chassis, and the angle is controlled by the piezoelectric actuator according to the amount of light received, so that the operator does not have to do manual work at high places Optical axis alignment can be performed automatically. A hinge, an elastic member, a spherical contact, etc. can be considered as the method of supporting so that rocking is possible like the above-mentioned embodiment.

  The present invention is useful as a smoke sensor in which a light emitter and a light receiver are disposed toward a monitoring space.

DESCRIPTION OF SYMBOLS 1 photoelectric type separation type sensor 10 light receiver 11 housing 12 optical bench 13 light receiving element 14 window 15 lens 16 hinges 17, 23, 25 support shafts 18, 24, 26 head of support shaft 19, 27 spring 20 piezoelectric actuator 21 Lead wire 22 control unit 28 first spherical surface portion 29 rising portion 30 second spherical surface portion 40 light emitter

Claims (14)

A smoke sensor comprising: a light emitter having a light emitting element; and a light receiver having a light receiving element, for detecting attenuation of light due to smoke in a monitoring space to detect a fire,
The light emitter is
An optical bench on which the light emitting element is mounted and which is swingably supported with respect to a housing;
A piezoelectric actuator interposed between the housing and the optical bench to change the tilt of the optical bench with respect to the housing;
Equipped with
The light receiver is
An optical bench on which the light receiving element is mounted and which is swingably supported with respect to a housing;
A piezoelectric actuator interposed between the housing and the optical bench to change the tilt of the optical bench with respect to the housing;
Equipped with
The smoke sensor which controls the said piezoelectric actuator of the said light emitter and / or the said light receiver based on the light reception amount by the said light receiver, and performs optical axis alignment of the said light emitter and the said light receiver.   The smoke sensor according to claim 1, wherein the light emitter and the light receiver are disposed to face each other across at least a part of the monitoring space.   The smoke sensor according to claim 1, wherein the light emitter and the light receiver are configured of one light receiver and light emitter, and have a reflecting plate facing the light emitter and light emitter.   A common optical bench supporting the light emitting element and the light receiving element is provided instead of the optical bench supporting the light emitting element and the light receiving element respectively, and it is interposed between the housing and the common optical bench The smoke sensor according to claim 3, further comprising: a piezoelectric actuator that changes the tilt of the optical bench with respect to the housing.   The smoke sensor according to any one of claims 1 to 4, wherein the light emitter and / or the light receiver includes a hinge that swingably supports the optical bench. The light emitter and / or the light receiver may
A spherical portion pivotally supporting the optical bench;
An elastic member that biases the optical bench against the spherical portion;
The smoke detector according to any one of claims 1 to 4, comprising: The light emitter and / or the light receiver may
A first spherical portion provided on the optical bench;
A second spherical portion formed on the housing in a shape corresponding to the first spherical portion and in surface contact with the first spherical portion;
The smoke detector according to any one of claims 1 to 4, comprising: A controller configured to control an orientation of an optical axis of the light emitter and / or the light receiver,
The control unit performs optical axis alignment between the light emitter and the light receiver based on an amount of light received when the value of the piezoelectric actuator of the light emitter and / or the light receiver is displaced at the time of initial setting. The smoke detector according to any one of 1 to 7. A controller configured to control an orientation of an optical axis of the light emitter and / or the light receiver,
The control method according to any one of claims 1 to 7, wherein when the amount of received light satisfies a predetermined condition at the time of operation, the control unit intermittently performs fire detection while performing optical alignment between the light emitter and the light receiver. Smoke detector as described in.   The smoke sensor according to claim 9, wherein the predetermined condition is that the amount of received light is higher than a fire detection threshold and lower than a first threshold for a predetermined time.   11. The smoke sensor according to claim 9, further comprising a notification unit for notifying that the light reception amount after the optical axis alignment does not reach the second threshold. An optical axis alignment method of a smoke detector which arranges a light emitter capable of controlling the light emission direction and a light receiver capable of controlling the light reception direction toward the monitoring space and detects a light attenuation by smoke to detect a fire. ,
Determining whether the amount of light received by the light receiver satisfies a predetermined condition;
When it is determined that the amount of light received by the light receiver satisfies a predetermined condition, fire detection is intermittently performed based on the amount of light received by the light receiver while performing optical alignment of the light emitter and the light receiver. The process to be performed,
Method of optical alignment of a smoke sensor comprising:   The method according to claim 12, wherein the predetermined condition is that the amount of light received is higher than a fire detection threshold and is lower than a first threshold for a predetermined time.   The method for optical axis alignment of a smoke sensor according to claim 12 or 13, further comprising the step of notifying that effect when the light reception amount after optical axis alignment does not reach the second threshold.

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