JP2840841B2 - Electric blinds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an electric blind mounted on a building, a vehicle, a ship, and the like, and more particularly, to a control device therefor.

<Conventional technology> Conventionally, the safety stop mechanism of the electric blind control device is
As disclosed in Japanese Utility Model Laid-Open No. 60-44993 or Japanese Utility Model Laid-Open No. 44994/1985, the upper and lower limit switches detect the rising end and the lowering end of the slat curtain, respectively, and stop the electric blind. As disclosed in Japanese Unexamined Utility Model Publication No. 61-102793 or the like,
For example, when the load on the motor increases when the slat curtain is finished ascending and the absolute value of the current flowing through the motor becomes larger than a preset value, a state to be stopped is detected and the electric blind is stopped. Alternatively, the position of an encoder or the like is detected using various sensors such as ultrasonic waves or light to stop the electric blind.

<Problems to be Solved by the Invention> In an electric blind using upper and lower limit switches, an increase in the number of parts related to the limit switches and an increase in cost for wiring work are inevitable. In addition, since there are various differences in the upper limit and lower limit to be stopped depending on the installation location or application, temporarily adjust the upper limit switch and lower limit switch at the time of factory shipment, and further operate the operation switch when installing the electric blind. Not only is it necessary to make full adjustments of the upper limit switch and the lower limit switch, but there is also a problem that readjustment is required due to aging of the limit switch.

In an electric blind controlled by the absolute value of the current flowing through the motor, the motor stops when the current reaches a preset current value. When the load on the motor increases, the motor current also increases and the motor stops unnecessarily, and in order to avoid this, it is necessary to reset the preset current value or increase the load current from the beginning. There is a problem that needs to be set. In addition, since the detection of the end of the lowering of the strut curtain requires a separate limit switch or the like, there is a problem similar to the case where the upper limit switch and the lower limit switch are used. Furthermore, if the bottom rail or the like hits an obstacle during the descent of the slat curtain, the motor current cannot reach the level required to stop the motor. This is because, generally, when the slat curtain is lowered, the motor to be driven is energized by the weight of the slat curtain, so that the motor is usually lightly loaded.
Therefore, even if an obstacle is present, the descent operation of the slat curtain is continued and the bottom rail and the like continue to descend, so that danger may occur depending on the type of the obstacle. For this reason, it is necessary to separately provide an obstacle detection mechanism at the time of descent. The set current value at which the motor should be stopped is determined by the motor current fluctuation due to the fluctuation of the mechanical loss when the slat curtain is raised or lowered, the current value increased by heating the motor due to the frequent operation of the electric blind, or in winter and summer. Since there are differences in current values due to differences in ambient temperature, it is difficult to set them.

Also, in the case of an electric blind using an ultrasonic sensor, both a transmitter and a receiver are required, and if an optical sensor is used, accessories such as an encoder are required,
In any case, there is a problem in that the number of parts increases, the cost of the electric blind increases, and the total weight increases.

<Means for Solving the Problems> The present invention provides an electric blind for raising and lowering a slat curtain by control means for driving or stopping a motor based on a drive or stop signal, in order to solve the above conventional problems. A change amount of the current flowing through the motor, and determining whether to drive or stop the motor based on the gradient value of the change. Means for detecting a current change amount to be taken out, means for differential approximation for obtaining a slope value of the current change amount, and a stop signal when the slope value exceeds a preset allowable maximum value or does not reach the allowable minimum value. And a comparing means for outputting

<Operation> If the motor load fluctuates while the slat curtain is moving up and down, the motor current detected by the current detecting means changes abruptly in the direction of increase or decrease. After the current change amount is detected by the current change amount detection means, the slope value of the current change amount is obtained by the differential approximation means, and based on the output signal from the differential approximation means, the comparison means detects the current change flowing through the motor. The slope value of the amount is compared with each of a preset maximum allowable value and a minimum allowable value. If the gradient value exceeds the maximum allowable value or does not reach the minimum allowable amount, a stop signal is sent to the control means. Is output, the motor stops, and the elevation of the slat curtain stops.

<Example> An example in which the electric blind of the present invention is attached to a building will be described.

In FIG. 1, a slat curtain 16 of an elevating member is wound up or rewinded by a winding mechanism 2. An input shaft of the winding mechanism 2 is connected to an output shaft of a reduction gear 3, and the reduction gear The output shaft of the motor 4 is connected to the input shaft 3. A drive circuit 12 controlled by a microcomputer with an analog-to-digital converter (hereinafter referred to as a microcomputer) 10 having a means for differential approximation, a comparing means and a control means is connected to the input of the motor 4.
Are connected via a motor current detector 5.
The motor current detector 5 replaces the instantaneous value of the motor current with a DC voltage and outputs it as a signal representing the absolute value of the motor current. The absolute value of the motor current detected by the motor current detector 5 is input to a motor current change amount detector 6, where only the change amount of the current flowing through the motor 4 is detected. The output signal of the detector 6 of the change amount of the motor current is amplified by the amplifier 7 and input to the microcomputer 10. The microcomputer 10 converts the signal input from the amplifier 7 into a digital value by performing an analog-digital conversion.
Further, after the differential approximation is performed by the differential approximation means, the operation of the motor 4 of the electric blind 1 during operation is stopped or continued by performing a comparison operation with the preset data by the comparison means. When the stop of the motor 4 is determined, a motor operation stop signal is sent to the control means, and the control means controls the drive circuit 12 to stop the operation of the motor.

Further, the microcomputer 10 rotates the motor 4 forward when receiving the electric blind rising signal output from the operating device 11, and receives the electric blind lowering signal when receiving the electric blind lowering signal.
When the slat adjustment signal of the electric blind is received, the motor 4 is rotated forward or backward several times at a fixed interval for a short time, and the motor 4 is stopped immediately when the stop signal of the electric blind is received, respectively. The drive circuit 12 is appropriately controlled based on the signal of (1).

The detector 6 for the change amount of the motor current is configured as shown in FIG. 2, for example. The input signal V1 converted from the current to the voltage by the motor current detector 5 is obtained by extracting an AC component by the capacitor C1, Biased by resistor R1 and integrated by resistor R2 and capacitor C2,
The signal is converted into an AC component signal V2 having an amplitude based on the voltage VC. In addition, when integration is performed in the motor current detector, the signal V1 itself has already been integrated, so that the resistor R2 and the capacitor C2 are unnecessary. The amplifier 7 amplifies the signal based on the voltage VC.

The differential approximation means and the comparison means in the microcomputer 10 are configured, for example, as shown in the flowchart of FIG. If an operation command has been output to the motor 4, the signal input from the amplifier 7 is converted from analog to digital (A / D conversion) at fixed minute time intervals into a digital value D1, and is updated in the RAM in the microcomputer. Is stored. This digital value D1 is to be compared with the digital value VCD of the reference voltage VC. If both values are almost the same, the signal input from the amplifier 7 is near the cross point with the reference voltage VC. Is determined. In the vicinity of the cross point, the absolute value of the derivative of the signal input from the amplifier 7 becomes almost maximum, and the gradient value of the amount of change of the motor current becomes almost maximum. , The next input signal is analog
The digital value is converted into a digital value D2, and the digital value D1 is converted.
The differential approximation of the input signal during the above-mentioned predetermined minute time is performed from the absolute value of the difference between the input signal and D2, and the absolute value of the slope value of the signal input from the amplifier 7 is calculated. The maximum allowable MX and minimum allowable absolute values of the above slope values are stored in the microcomputer.
MY are preset, respectively. First, the absolute value of the slope value is compared with the allowable maximum value MX, and when the absolute value of the slope value exceeds the allowable maximum value MX, that is, the current flowing through the motor 4 suddenly and abnormally increases. When the fluctuation occurs, the stop of the motor 4 is determined, a motor operation stop signal is sent to the control means, and if the absolute value of the slope value does not exceed the allowable maximum value MX, the absolute value of the tilt value and the allowable minimum value MY And the absolute value of the slope value is the minimum allowable value
When the current does not reach MY, that is, when the current flowing through the motor 4 hardly changes, the stop of the motor 4 is determined, and a motor operation stop signal is sent to the control means.

Note that the above-mentioned permissible maximum value is a normal value caused by uneven rotation of the motor 4, fluctuation of mechanical loss due to elevating and lowering of the slat curtain 16, or contact with a wind hitting the slat curtain 16 or an obstacle that does not cause any trouble. In consideration of the fluctuations of the motor current in the operating state, the values of these fluctuations are set to values larger than the absolute value of the differential value approximated at the cross point of the AC component signal with the reference voltage VC. The above-mentioned permissible minimum value refers to a failure of the output shaft of the motor 4, a failure of the winding mechanism 2, or a failure of the slat curtain 16 and a bottom rail 15 hitting the floor surface or a window frame, etc., and the fluctuation of the motor current is reduced. Since it is necessary to detect the extremely low state, the absolute value of the gradient value that is differentiated and approximated in the vicinity of the cross point between the AC component signal and the reference voltage VC of the motor current fluctuation at the time of the abnormality is larger than the normal operation. The value is set to a value smaller than the absolute value of the slope value of the state. If the motor current fluctuates suddenly and abnormally during normal operation, or if the motor current fluctuates extremely less than during normal operation, the comparison means in the microcomputer 10 controls the current change. The stop signal is output in a state where the slope value of the amount exceeds the allowable maximum value or does not reach the allowable minimum value, and the control circuit in the microcomputer 10 controls the drive circuit 12 so that the motor 4 stops immediately. Control is done.

The sudden and abnormal fluctuation in the motor current that occurs during the normal operation is that when the slat curtain 16 is completely lifted and the slats 13 are all wound up to the top and in a stacked state, the bottom rail 15 still rises When the load of the motor 4 suddenly increases due to the start of compressing the laminated body of the slats 13 or when the lowering of the slat curtain 16 is completed, the lifting tape 14 supporting the bottom rail 15 is completely extended, and the winding of the lifting tape 14 is performed. When the load of the motor 4 suddenly changes because the pulley for rewinding starts idling,
Alternatively, when the moving member such as the bottom rail 15 hits a floor, a window frame, an obstacle, or the like before the elevating tape 14 is fully extended while the slat curtain 16 is being lowered, and the load of the motor 4 is suddenly changed, or when the slat curtain 16 is being raised. This corresponds to a case where a moving member such as the slat 13 or the bottom rail 15 is caught by an obstacle and the load of the motor 4 is rapidly increased.
Further, when the fluctuation of the motor current is extremely small as compared with the normal operation, for example, the state in which the elevating tape 14 is completely extended, or the state in which the bottom rail 15 is
Although the slat curtain 16 stops in a state where the slat curtain 16 cannot be further lowered due to hitting a floor surface, a window frame, an obstacle, or the like, a descent command is suddenly input from the operating device 11 at the time of re-energization after a power failure. And so on.

The input to the operation device 11 can use not only a toggle switch or a push button switch, but also an infrared remote control system that is widely used in ordinary households, and a human voice input using a voice recognition device. Can be used.

<Effect of the Invention> The present invention is to stop the electric blind safely based on the gradient value of the amount of change in the current flowing through the motor. The various types of expensive sensors are unnecessary, the number of parts is reduced, the number of assembly steps is reduced, and the cost of the electric blind is reduced.On the other hand, when installing the electric blind, adjustment of various switches or sensors is unnecessary. Therefore, there is a feature that does not require a construction specialist.

In addition, regardless of the absolute amount of current flowing through the motor, the safety stop function operates by detecting only the change in the load condition that directly acts on the slat curtain during ascent and descent. And inconvenience such as setting of prospects do not exist. Furthermore, when the slat curtain hits an obstacle during the ascent, or when all of the slats are wound up to the top and the ascent is completed, there is a conventional electric blind controlled by the absolute value of the current flowing through the motor. It is possible to stop the motor before it reaches the mechanical lock state of the winding mechanism, which is apt to occur, and the abnormal overload state of the motor accompanying this, and fatigue deterioration is alleviated and the quality and life are excellent. On the other hand, on the other hand, the mechanical strength of the components such as the winding mechanism is not so required, so that the components can be made of a lightweight and inexpensive material. Also, when the slat curtain hits an obstacle during the descent, the descent is stopped immediately, so that danger to the obstacle can be avoided without providing an additional obstacle detection mechanism or the like.

Further, even when the slat curtain hits an obstacle or stops at the end of descent at the time of re-energization after a power failure, even if a descent command is suddenly input, There is a feature that the motor can be stopped by detecting this state in a specific manner.

[Brief description of the drawings]

1 shows an embodiment of the present invention, FIG. 1 is a block diagram for explaining the configuration and function, FIG. 2 is a circuit diagram showing an example of a means for detecting a change in motor current in FIG. 1, and FIG. Is the first
It is a program flowchart of the microcomputer of the figure. 1: electric blind, 4: motor, 8: current detection means,
9: means for detecting the amount of change in current; 10: microcomputer with analog-digital converter; 16: slat curtain.

Claims (1)

(57) [Claims] An electric blind for raising and lowering a slat curtain by control means for driving or stopping a motor based on a drive or stop signal, a current detection means for detecting a current flowing through the motor, and a variation of the current is taken out. Means for detecting a current change amount, means for differential approximation for obtaining a slope value of the current change amount, and a stop signal when the slope value exceeds a preset allowable maximum value or does not reach the allowable minimum value. An electric blind characterized by comprising a comparing means for outputting.