JP2000045663A - Fire shutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire shutter for performing safety operation including stopping operation if obstacles are sensed during move-down operation and resuming move-down operation immediately after the obstacles are removed. SOLUTION: When a fire signal is received, move-down operation is started at S11 and the move-down operation is continued with looping of S11, S12, S16, S15. When an obstacle sensing signal is received during move-down operation, the move-down ?operation is stopped with transition from S12 to S13 to await end the removal of obstacles after advance to S14. When the obstacles are removed, an obstacle sensing part sends an extinction signal and a control part receiving the extinction signal resumes move-down operation after setting back from S14 to S11. When a signal from a sensor sensing that a person comes near to a shutter during move-down operation is received, move-down operation is stopped with transition from S16 to S17 and the move-down operation is resumed with setting back to S11 after a certain time at S18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fireproof shutter for closing a fire in a fire to prevent the spread of the fire.

[0002]

2. Description of the Related Art Fireproof shutters are provided to prevent fire from spreading in the event of a fire, and are installed, for example, at the boundary between a staircase area and a room area such as a store. About fire prevention shutter,
The Building Standards Law stipulates that the structure should automatically close when a fire occurs.

[0003] Driving of the fireproof shutter includes an electric shutter in which the raising and lowering operations of the shutter are performed by an electric motor, and a manual shutter having no electric motor for winding. In the electric shutter, the motor is driven by a fire signal to lower the shutter to perform a closing operation. In the manual shutter, the braking mechanism is released by a fire signal and lowered by its own weight to perform a closing operation.
Further, even with an electric shutter, if a fire and a power failure overlap with each other or a power failure occurs due to a fire, the motor cannot be driven to close the shutter. Therefore, even in the case of an electric shutter, as a method of automatically closing the shutter in response to a power failure, the braking mechanism can be released similarly to the manual shutter, and in the case of a power failure, a fire signal To release the braking mechanism and descend by its own weight. In the electric shutter and the manual shutter, a standby power source such as a battery is used as a power source of a driving mechanism for releasing a braking mechanism, thereby coping with a power failure.

In these shutter facilities, if there is an obstacle at the lower position of the shutter during the lowering operation, if the lowering is continued as it is, the obstacle will be pinched. Depending on the obstacle, the shutter may be damaged or an unexpected accident may occur if the obstacle is a refuge.

In order to prevent this, an obstacle sensing unit is provided in the shutter, and when the descending shutter touches an obstacle, the shutter is stopped from descending, or is inverted and raised for a predetermined time after the shutter is stopped. There is known a safety shutter for performing control.

[0006] The fireproof shutter that performs the closing operation by the signal from the fire alarm is not limited to the electric shutter and the manual shutter, but also enables the stopping operation and the re-elevating operation when an obstacle is touched during the closing operation. It is important to equip such a safety mechanism.

The obstacle sensing unit used in the safety mechanism employs a mechanism for sensing that the shutter seat plate has come into contact with an obstacle. A conventionally used mechanism uses a seat plate switch which is provided with a contact plate on a seat plate portion and which is activated by the contact plate being pushed up by contact with an obstacle. A wireless signal such as an infrared ray or a radio wave is transmitted by the operation of the seat plate switch to notify the shutter control unit that an obstacle has been detected, and control the descending operation.

FIG. 5 is a flowchart showing an example of the closing operation when the electric shutter equipped with the safety mechanism receives a fire signal. When the control unit of the shutter receives the fire signal, the descending operation is started in S21. S21,
If S22 and S27 are looped and the obstacle detection signal is not received while the descending operation is continued, S2 is performed.
At 7, the lower limit is stopped, and the flow ends. Of course, the shutter is completely closed.

When an obstacle sensing signal is received, the process proceeds from S22 to S23 to stop the descending operation, and then proceeds to S25 to reverse and ascend. After a predetermined period of time or a predetermined height reversal rise, in S26, the process is stopped for a certain period of time, and the process returns to S21 to resume the descending operation. Hereinafter, this operation is repeated. Therefore, in the course of the re-lowering operation, if an obstacle is detected, reversal and re-up and re-lowering are repeated, so that if the obstacle is removed, it can be completely closed.

As described above, by transmitting an obstacle sensing signal from the obstacle sensing unit to the control unit of the shutter, it is possible to prevent a danger that the evacuated person is stuck between the descending shutters and cannot move. Becomes

A battery is used as a power source of the obstacle sensing unit. When the detection of an obstacle is performed using the seat switch and the wireless signal is transmitted when the seat switch is turned on, the wireless signal is continuously transmitted while the seat switch is on. In this case, battery consumption becomes a problem. In particular, when the seat panel switch is turned on and the wireless signal is continuously transmitted in a closed state where the shutter is grounded to the floor, the battery is consumed in a short time, which is not practical.

Therefore, in the obstacle sensing unit, the power is turned on and the radio signal is transmitted by turning on the seat plate switch, but the power is turned off after a predetermined time by the timer means. Therefore, even if the seat panel switch is kept on, the wireless signal is transmitted only for a short time, and battery consumption can be suppressed.

In the case where the fire shutter is equipped with an obstacle sensing unit and incorporates a safety mechanism, if the operation described with reference to FIG. 5 is performed, the seat plate switch is turned off by reversing and rising. Even if an obstacle is detected during the descent, a radio signal is transmitted and safe operation is possible even when the descent is completed.If the obstacle is removed and no obstacle is detected during the descent, the complete It is possible to have a closure. Therefore, even if the seat panel switch continues to be in the ON state, it is not necessary to continuously transmit the wireless signal, and it is only necessary to transmit the wireless signal for a short time.

However, in the case of an electric shutter incorporating a safety mechanism, when an obstacle is detected, the electric shutter shown in FIG.
In some cases, the number of repetitions of the series of operations of reversing ascending, stopping for a certain period of time, and descending again is limited to a predetermined number.

FIG. 6 is an example of a flow chart in which the number of repetitions of a series of operations of reversing ascending, stopping for a certain period of time, and descending again is limited to a predetermined number. In the figure, the same steps as those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. In this flowchart, the number of repetitions is counted, and when the descent is stopped in S23, if the predetermined number is reached, the flow is terminated from S24. In some cases, S24 and S25 are interchanged and reversed.

In the shutter that performs such an operation, if a fire signal is received and the removal of an obstacle is delayed, the shutter continues to stop at the position where the obstacle is detected, and then the obstacle is removed. However, the closing operation cannot be performed. In the flow in which S24 and S25 are reversed, the shutter continues to stop at the re-elevated position,
Even if the obstacle is subsequently removed, the closing operation cannot be performed.

In addition to the flowchart of FIG. 6, when a sensing signal is received from the obstacle sensing unit during the descending operation, the operation is immediately stopped when the obstacle is sensed, and the operation of maintaining the stopped state is performed. Even when the obstacle is removed, the closing operation cannot be performed even if the obstacle is removed.

In the flow described with reference to FIG. 5, even if the obstacle is removed at the time when the inversion rise is started, after the total time of the inversion rise time in S25 and the fixed time in S26 has elapsed. If not, the lowering is not performed, so that the time until the complete closing is delayed, which is not preferable in the case of the closing operation by the fire signal, regardless of the normal closing operation.

When the control unit of the manual shutter receives a fire signal, or when the control unit of the electric shutter receives a fire signal in the event of a power failure, power is supplied from the emergency power supply, as shown in FIG. Such an operation is performed. That is, the descending operation is started in S11, and S11, S12, S
If the obstacle detection signal is not received while the descending operation is continued while looping the loop 15, the lower limit is stopped in S15 and the flow is terminated. Of course, the shutter is completely closed. When an obstacle sensing signal is received,
The process moves from S12 to S13 to stop the descending operation and end the flow. Thus, in the flow of FIG.
If the descending operation is stopped in S13 after the detection signal of the obstacle is received at 12, the ascent is not performed again. Therefore, even if the obstacle is removed thereafter, the closing operation cannot be performed.

As described above, in the conventional obstacle sensing unit, when an obstacle is sensed, only a radio signal is transmitted for a short period of time.
There is a problem that the closing operation cannot be performed or the closing operation is delayed.

However, there is also a problem that when the fire prevention shutter is lowered by a fire signal at the time of a fire, the passage is blocked and evacuation cannot be performed. An evacuation door is installed adjacent to the fire shutter to secure an evacuation route.However, some evacuees who are still calm do not notice the evacuation door, Some seek to evacuate underneath. When the vehicle passes under the descending shutter, the obstacle sensing unit operates to perform the above-described stop operation and reversal ascending operation, but the operation is not necessarily perfect. It is therefore dangerous to pass under a descending shutter.

[0022]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and when an obstacle is detected during a descending operation, the obstacle is removed by a fireproof shutter that performs a safety operation such as stopping. Then, the descending operation can be resumed immediately, and the object is to provide a safer fireproof shutter by stopping descending when a person approaches the fireproof shutter being descended.

[0023]

According to a first aspect of the present invention, there is provided a fireproof shutter which receives a fire signal and starts a closing operation, wherein a person approaches an obstacle sensing unit and the vicinity of the fireproof shutter. And a control unit that controls a lowering operation of a shutter based on the outputs of the obstacle sensing unit and the sensor unit, wherein the obstacle sensing unit detects that an obstacle has been sensed. A sensing signal indicating that the obstacle has been removed, and a disappearing signal indicating that the obstacle has been removed can be transmitted as a wireless signal to the control unit, and the control unit stops lowering the shutter based on the output of the sensor unit. The shutter is controlled as follows.

According to a second aspect of the present invention, in the fireproof shutter according to the first aspect, the sensing signal and the extinction signal have the same signal content.

According to a third aspect of the present invention, in the fireproof shutter according to the first aspect, the sensing signal and the extinction signal have identifiable signal contents.

According to a fourth aspect of the present invention, there is provided a fireproof shutter which receives a fire signal and starts a closing operation, comprising an obstacle sensing unit and a sensor for detecting that a person has approached the vicinity of the fireproof shutter. Unit, and control means for controlling the lowering operation of the shutter based on the output of the obstacle sensing unit and the sensor unit, when the control means receives a sensing signal indicating that an obstacle has been sensed Stopping the lowering operation, restarting the lowering operation when receiving a disappearance signal indicating that the obstacle has been removed, and controlling the shutter to stop the lowering of the shutter based on the output of the sensor unit. It is a feature.

According to a fifth aspect of the present invention, there is provided a fireproof shutter which receives a fire signal and starts a closing operation, wherein an obstacle detecting unit and a sensor for detecting that a person approaches the vicinity of the fireproof shutter. Unit, and control means for controlling a lowering operation of a shutter based on outputs of the obstacle sensing unit and the sensor unit, and the obstacle sensing unit includes a seat plate switch that is activated by sensing an obstacle. Based on the switching of the seat plate switch from the off state to the on state, and based on the switching from the on state to the off state,
A wireless signal is transmitted, and the control unit controls the shutter to stop the lowering of the shutter based on an output of the sensor unit.

According to a sixth aspect of the present invention, in the fireproof shutter according to the fifth aspect, the signal content of the radio signal transmitted based on switching of the seat plate switch from the off state to the on state, and the on state The wireless signal transmitted based on the switching from the state to the off state has the same signal content.

According to a seventh aspect of the present invention, in the fireproof shutter according to the fifth aspect, the signal content of the radio signal transmitted based on the switching of the seat plate switch from the off state to the on state, and the on state The signal content of the wireless signal transmitted based on the switching from the state to the off state is different.

According to an eighth aspect of the present invention, in the fireproof shutter according to any one of the first to seventh aspects, the control means stops the lowering of the shutter and then lowers it after a lapse of a predetermined time. It is characterized by the following.

[0031]

FIG. 1 is an explanatory view of an example of an embodiment of a sensor section for detecting that a person has approached a vicinity of a fire prevention shutter. In the figure, 1 is a building frame, 2 is a take-up drum, 3 is a shutter slat, 4, 5 are ultrasonic sensors,
Reference numerals 6 and 7 denote photoelectric sensors.

FIG. 3 shows a state in which the shutter slat 3 is lowered to the lower limit position and the passage is closed. Normally, the shutter slat 3 is wound up by the winding drum 2 to open a passage. As described above, when a fire signal is issued or the down switch is operated, the shutter slat 3 starts to descend. During the descent, when a person enters near the descent area of the shutter slat, the sensor unit detects this. As an example of the sensor unit, the ultrasonic sensors 4 and 5 are arranged near the ceiling, and the photoelectric sensors 6 and 7 are arranged at a height where human traffic can be detected, for example, about 1 m. The ultrasonic sensors 4 and 5 emit ultrasonic waves and receive reflected waves. In this method, a moving object such as a person is detected, and the reception input of the ultrasonic wave is fluctuated by the moving object to detect a person. The sensor attached near the ceiling is not limited to an ultrasonic sensor, and an infrared sensor or the like that detects infrared rays emitted by a person may be used. Photoelectric sensor 6,
Reference numeral 7 receives a light beam from a light source (not shown). The projection path of the light beam from the light source to the photoelectric sensor approaches the shutter slat 3 such that a person such as an evacuee traverses a path approaching the installation area of the shutter slat 3, for example, separate from the shutter slat 3 and becomes parallel. The installation positions of the light source and the photoelectric sensors 6, 7 are determined so that light incident on the photoelectric sensors 6, 7 can be blocked before a person reaches the position of the shutter slat.

In this embodiment, the ultrasonic sensors 4 and 5
Although the photoelectric sensors 6 and 7 are provided on both sides of the shutter slat 3, they may be provided on only one side depending on the installation location of the shutter with respect to the movement path of the person. Further, the number and position of the sensors provided on each side may be appropriately determined.
In addition, a sensor provided on the ceiling side such as the ultrasonic sensors 4 and 5 and a sensor provided near the floor surface such as the photoelectric sensors 6 and 7 may be only one of them. May be used. of course,
The ultrasonic sensor and the infrared sensor do not necessarily need to be provided near the ceiling, and may be provided on the wall surface. Further, a pressure sensor may be provided on the floor surface.

FIG. 2 is a flowchart for explaining a first embodiment of the fireproof shutter according to the present invention. This flowchart is a flowchart in the case where the control unit of the manual shutter receives a fire signal or the case where the control unit of the electric shutter receives a fire signal in the event of a power outage, as described with reference to FIG. When a fire signal is received, S11
, The descending operation is started, and S11, S12, S16, S1
5, the descending operation is continued, but when the lower limit position is reached, the lower limit is stopped in S15, the flow ends, and the shutter is completely closed.

When the control unit receives a sensing signal from the obstacle sensing unit during the lowering operation, the process shifts from S12 to S13 to stop the lowering operation, proceeds to S14, and waits for the removal of the obstacle. When the obstacle is removed, the obstacle sensing unit transmits the disappearance signal, and the control unit that has received the disappearance signal returns from S14 to S11 and restarts the descending operation. Thereafter, if no sensing signal of the obstacle or the sensor signal from the sensor unit is received, the flow ends through S12 to S15.
If the obstacle detection signal is received during the re-fall, the process proceeds from S12 to S13 and S14 to wait for the reception of the obstacle disappearance signal.

When the control unit receives a sensor signal from the sensor unit during the lowering operation, the process proceeds from S16 to S17 to operate the braking unit of the braking mechanism to stop the lowering operation, and then to S18.
And stop for a certain period of time. After a lapse of a certain time, the process returns to S11, and S11, S12, S16, S
It enters a loop of No. 15 and restarts the descending operation.

As described above, when a person approaches the shutter during the descending operation and the sensor detects a person, the descending shutter slat stops descending, so that the person is caught by the descending shutter slat. Can be prevented. Therefore, it is possible to prevent the evacuee from being caught by the descending shutter slats due to the fire signal. Furthermore, since the descending operation is resumed after a certain period of time, the closing operation by the shutter slat at the time of fire can be performed.

An obstruction disappearance signal will be described. As described above, from the viewpoint of suppressing power battery consumption, the obstacle sensing unit operates for a short time to transmit the obstacle sensing signal, and transmits the obstacle sensing signal, from the viewpoint of suppressing power battery consumption. Turn off. Therefore, even if the obstacle detection state continues, the power is turned off, so that battery consumption can be prevented. When the obstacle detection signal disappears due to the removal of the obstacle from the obstacle detection state, similarly,
Turn on the power for a short time and send the extinction signal. As described above, when the control unit receives the disappearance signal, the re-lowering operation is performed.

The sensing signal transmitted when an obstacle is sensed and the disappearance signal transmitted when the obstacle is removed while the obstacle sensing state continues are transmitted when the power is turned on for a short time. It is not limited to doing.

For example, in an obstacle sensing unit in which an obstacle is sensed by a seat switch, the on / off state of the seat switch is monitored by detecting the voltage on the output circuit side of the seat switch. However, the change from the on state to the off state and the change from the off state to the on state may be detected while the power is always on. Since the current for detecting the voltage may be very small, it can be set to a state close to the spontaneous discharge of the battery. As described above, the current of the circuit for detecting the voltage is always made to flow, and the transmission of the radio signal is performed for a short time only when the on / off state changes. Transmission of radio signals
Although a large current is required, the battery is consumed for a short time. The detection of the voltage by turning on / off the seat plate switch may be performed intermittently at predetermined time intervals. In this case, if the ON / OFF state of the seat panel switch is determined based on a plurality of detection values, monitoring that is not affected by the chattering of the switch can be performed.

The signal content of the extinction signal is preferably different from the signal content of the sensing signal. For example, in the case where the sensing signal is transmitted as a digital signal, the signal code is different between the sensing signal and the extinction signal. In the control unit, it is easy to identify whether the signal is a sensing signal or an extinguishing signal, and control can be performed according to the signal content.

However, the signal content of the extinction signal may be the same as the signal content of the sensing signal. In the control unit, based on information such as the operation state of the shutter and the position of the shutter (which can be determined by a limit switch or the like), the received signal is a signal indicating that an obstacle has been detected, or the obstacle has disappeared. Thus, it is possible to identify whether or not the signal is a result of the control, and control the shutter.

FIG. 3 is a flowchart for explaining a second embodiment of the fireproof shutter according to the present invention. As described with reference to FIG. 6, in this flowchart, the number of times that a series of operations of reversing up, stopping for a certain period of time, and re-lowering when an obstacle is detected is repeated to a predetermined number in the electric shutter having the obstacle sensing unit. It is an example of the flowchart which was made to restrict. In the figure, the same steps as those in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted. In this flowchart, the number of repetitions is counted, and when the descent is stopped in S23, if the number of repetitions is a predetermined number, the process proceeds from S24 to S28 and waits for reception of the disappearance signal. When the obstacle is removed, the obstacle sensing unit transmits the disappearance signal, and the control unit that has received the disappearance signal shifts from S28 to S29, resets a counter for counting the number of repetitions, and returns to S21. Restart the descending operation. Thereafter, if the obstacle sensing signal and the sensor signal from the sensor unit are not received, the flow ends through S22 to S27. If an obstacle sensing signal is received during the descent, the process proceeds to S23 and the above-described operation is repeated.

When a disappearance signal is received during a loop of S21 to S26 in which a series of operations of reversing ascending, stopping for a predetermined time, and re-falling is repeated, interrupt processing is immediately performed to execute S.
You may make it jump to 21. After the obstacle is removed, the closing operation can be performed in a short time.

When a sensor signal from the sensor section is received during the lowering operation, the process proceeds from S30 to S31, where the lowering operation is stopped, the process proceeds to S32, and the reversing and rising is performed so as to reach a predetermined height. The height of the reversal rise is preferably a predetermined height so that the shutter does not pinch the evacuated person, and a limit switch for that purpose may be provided. If the sensor signal is received when the shutter slat is at a position higher than the predetermined height, the shutter slat does not reverse up. After reversing and rising,
In S33, the operation is stopped for a predetermined time, for example, several minutes, and the process returns to S21 to resume the lowering operation. Note that the sensor unit includes one sensor or two or more sensors as described with reference to FIG. Further, the reversal and rise in S32 may not be performed.

As described above, when a person approaches the shutter during the descending operation and the sensor detects a person, the descending shutter slat stops descending or reverses and ascends after stopping. It is possible to prevent the shutter slat being lowered from being pinched. Therefore, it is possible to prevent the evacuee from being caught by the descending shutter slats due to the fire signal. Furthermore, since the descending operation is resumed after a certain period of time, the closing operation by the shutter slat at the time of fire can be performed.

FIG. 4 is a flowchart for explaining a third embodiment of the fireproof shutter according to the present invention. This flowchart is such that in the second embodiment described with reference to FIG. 3, a series of operations of reversing and rising, stopping for a certain time, and re-falling when an obstacle is detected are not repeated. That is, when the sensing signal is received during the descending operation, the process proceeds from S22 to S23 to stop the descending operation,
At 25, it inverts and rises for a fixed time or a fixed height and stops, and waits for the reception of the disappearance signal at S28. When the obstacle is removed, the obstacle sensing unit transmits a disappearance signal, and the control unit that has received the disappearance signal returns from S28 to S21 and restarts the descending operation. Thereafter, if no obstacle detection signal is received, the flow ends through S22 to S27. If an obstacle sensing signal is received during the descent, the process proceeds to S23 and the above-described operation is repeated.

In this embodiment, when an obstacle is sensed, a series of operations of reversing up, stopping for a certain period of time, and re-lowering is prevented from being repeated. In such a system, the emergency power supply can be prevented from being consumed.

In the third embodiment, a reversal rise may not be performed. In that case, in FIG.
Although this corresponds to the flow from which S25 is deleted, the present invention is not limited to these embodiments. By receiving the extinction signal, in the operation shown in the flowchart of FIG. 5 as well, the closing operation can be performed immediately by the interruption process to shorten the closing time.

When a sensor signal is received from the sensor section during the descending operation, the stop operation, the reversal ascent operation, and the stop operation for a predetermined time are performed in steps S31 to S33 as in the second embodiment described with reference to FIG. May be performed, but the reversal rising operation of S32 may not be performed.

The obstacle sensing unit is not limited to the one using the seat plate switch, but may be a pressure sensitive means such as a resistance strain gauge or a semiconductor strain gauge, or an infrared sensing unit from a person or an animal. Appropriate detection means such as infrared detection means can be used.

[0052]

As is apparent from the above description, according to the present invention, in a shutter having an obstacle sensing unit,
After detecting the obstacle and stopping the lowering operation, if the obstacle is removed, the lowering operation can be restarted, the shutter can be closed, and a person approaching the shutter during the lowering operation is detected. In addition, since the descending operation is stopped at least, there is an effect that a safer fireproof shutter can be provided.

When the shutter is lowered by the down button or when the fire signal is generated due to a malfunction and the shutter is lowered, the above-described operation is performed, so that a person approaching the shutter during the lowering operation is detected. In this case, the descending operation can be stopped, which is safer.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of an embodiment of a sensor unit that detects that a person has approached a vicinity of a fire prevention shutter.

FIG. 2 is a flowchart illustrating a first embodiment of a fireproof shutter according to the present invention.

FIG. 3 is a flowchart for explaining a second embodiment of the fireproof shutter of the present invention.

FIG. 4 is a flowchart illustrating a third embodiment of a fireproof shutter according to the present invention.

FIG. 5 is a flowchart illustrating an example of a closing operation when an electric shutter equipped with a safety mechanism receives a fire signal.

FIG. 6 is a flowchart showing another example of the closing operation when the electric shutter equipped with a safety mechanism receives a fire signal.

FIG. 7 is a flowchart showing another example of the closing operation when the electric shutter equipped with the safety mechanism receives a fire signal.

Claims (8)

[Claims] 1. A fire prevention shutter for receiving a fire signal and starting a closing operation, comprising: an obstacle detection unit; a sensor unit for detecting that a person approaches the vicinity of the fire prevention shutter; Unit and control means for controlling the lowering operation of the shutter based on the output of the sensor unit,
The obstacle sensing unit is capable of transmitting a sensing signal indicating that an obstacle is sensed, and a disappearance signal indicating that the obstacle has been removed to the control unit as a wireless signal, and the control unit includes: A fireproof shutter, wherein the shutter is controlled so as to stop the lowering of the shutter based on an output of the sensor unit. 2. The fireproof shutter according to claim 1, wherein the sensing signal and the extinction signal have the same signal content. 3. The fireproof shutter according to claim 1, wherein the sensing signal and the extinction signal have identifiable signal contents. 4. A fire protection shutter for receiving a fire signal and starting a closing operation, comprising: an obstacle detection unit; a sensor unit for detecting that a person approaches the vicinity of the fire prevention shutter; Unit and control means for controlling the lowering operation of the shutter based on the output of the sensor unit,
The control means stops the descending operation when receiving a sensing signal indicating that an obstacle has been sensed, and restarts the descending operation when receiving a disappearance signal indicating that the obstacle has been removed, A fire shutter, wherein the shutter is controlled so as to stop the lowering of the shutter based on an output of a sensor unit. 5. A fire shutter for receiving a fire signal and starting a closing operation, comprising: an obstacle sensing unit; a sensor unit for sensing that a person approaches the vicinity of the fire shutter; Unit and control means for controlling the lowering operation of the shutter based on the output of the sensor unit,
The obstacle sensing unit has a seat switch that is activated by sensing an obstacle, based on switching the seat switch from an off state to an on state, and based on switching from an on state to an off state. And transmitting a wireless signal, wherein the control means controls the shutter to stop the lowering of the shutter based on the output of the sensor unit. 6. A signal content of a radio signal transmitted based on switching of the seat plate switch from an off state to an on state, and a signal content of a radio signal transmitted based on switching from an on state to an off state. 6. The fireproof shutter according to claim 5, wherein 7. A signal content of a wireless signal transmitted based on switching of the seat plate switch from an off state to an on state, and a signal content of a wireless signal transmitted based on switching from an on state to an off state. 6. The fireproof shutter according to claim 5, wherein 8. The fireproof shutter according to claim 1, wherein the control unit stops lowering the shutter and then lowers the shutter again after a lapse of a predetermined time.