JP2006307471A - Electric shutter overload detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric shutter overload detection device capable of surely and inexpensively detecting an overload state of the electric motor by simply controlling in a shutter device making use of the electric motor. <P>SOLUTION: The electric shutter overload detection device is so constituted that even if a factor enabling the revolution- speed of a DC motor to fluctuate occurs, a constant speed controlling means maintaining the revolution-speed in winding up or down by controlling a driving current of the DC motor, a positional detection means organizing position information regarding to a winding up position or a winding down position of a shutter curtain, a load detection means organizing load information regarding to a load state of the DC motor by finding a current value of the driving current, the load information is memorized in relation with the positional information and, at the same time, a load storage means which the load information corresponding to the memorized positional information referred in an operating state of the electric shutter device are included. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric shutter overload detection device, and can be applied to, for example, an electric shutter overload detection device controlled by a microcomputer.

FIG. 8 is a perspective view for explaining an electric shutter device and the like according to a conventional example.
Conventionally, a powerful electric shutter device has been installed at the entrance of a store. The electric shutter device 9 shown in FIG. 8 is provided with a shutter curtain having a plurality of slats 92, 92... And the winding drum 95 rotated by the drive part 94 by the electric motor 93 is wound up to form an opening, and is wound down to close the opening. The drive unit 94 is wired or provided with a power source (AC 100 V), an operation unit wall switch, an emergency release lever, and the like.

  In general, the electric shutter device 9 needs a mechanism that prevents it from being accidentally pulled into the shutter, not only for passers-by and imported goods, but also for equipment around the device, advertising banners, and the like. That is, when the operation of the shutter curtain is hindered by an obstacle or the like, the electric motor 93 can be overloaded, and thus a device for detecting an overload state in which the electric motor 93 is overloaded is required. And the load of the electric motor 93 is restrained in the tolerance | permissible_range according to the scheduled rotational speed, for example by such a detection apparatus. In addition, various detection devices have been proposed in which the permissible range is set as a memory management table to improve motor control efficiency.

JP 2002-1941973 A

However, the conventional techniques as described above have the following problems.
(1) Generally, in an electric shutter device, a relatively powerful AC motor is used in combination with an inexpensive control device, and the load of the motor is calculated by conversion processing based on the number of rotation pulses. Therefore, this conversion process must be performed simultaneously by, for example, a control device, which causes an extra circuit burden and an increase in cost.
(3) Further, in order to reliably determine overload, the voltage and frequency of the driving power must always be stabilized, and correction values such as these voltages are described in each correction table. Therefore, since it is necessary to equip a memory element having a large memory capacity and to refer to them sequentially, the control device becomes inevitably expensive, resulting in a further increase in circuit load and cost. It is had.
(2) In such a load management table, the value of the allowable range must be described in advance for all the steps of motor control, so that the circuit cost is pressed by the enlarged management table. Or, if you describe only with limited points on the process, the accuracy of the management value will be coarse, so when determining the overload state, it is necessary to further widen the allowable range to eliminate the variation etc. It has become extremely difficult to construct a control system at a low cost and in a well-balanced manner.

  The present invention has been made in view of the above circumstances, and in an shutter device using an electric motor, an electric shutter overload detection device capable of reliably and inexpensively detecting an overload state of the electric motor by simple control. The purpose is to provide.

In order to achieve the above object, an electric shutter overload detection device according to claim 1 is an electric shutter that winds up a shutter curtain by a DC motor to form an opening, and lowers the shutter curtain to close the opening. In the device, an electric shutter overload detection device that detects an overload state in which winding and lowering are hindered,
Constant speed control means for controlling the rotational speed to a constant speed even if a factor that can vary the rotational speed of the DC motor occurs,
Position detecting means for knitting position information relating to the winding position or lowering position of the shutter curtain by detecting the rotational speed of the DC motor;
Load detecting means for organizing load information related to the load state of the DC motor by detecting the current value of the drive current;
The load information is stored in association with the position information, and the load information corresponding to the stored position information is referred to in the operating state of the electric shutter device. .

In the invention described in claim 1, a DC motor is used as the electric motor. In addition, each process of the control circuit is initialized in advance, including position information such as a shutter curtain winding position and DC motor load information. Examples of such a control circuit include a circuit using a programming system such as a microprocessor or a sequencer.
First, the driving current of the DC motor is controlled to maintain the rotational speed of the DC motor by constant speed control means during winding. As a result, the DC motor can rotate at a constant speed. During this control, the position detection means detects the rotational speed of the DC motor and organizes positional information for control such as winding based on this rotational speed. Further, the current value of the drive current is detected by the load detection means, the load information of the DC motor is organized based on this current value, and is stored in association with the position information by the load storage means. When operating the electric shutter device, when the shutter curtain is operated while controlling the DC motor at a constant speed, the stored load information is referred to and used for each process of overload detection.

  According to a second aspect of the present invention, there is provided the electric shutter overload detection device according to the first aspect, wherein the constant speed control means corrects a drive current in accordance with a detected temperature of the DC motor. .

  In the second aspect of the present invention, even if the direct current motor has a slight change in magnetization characteristics or the like due to self-heating, the drive current is corrected with a temperature rise or the like by a set value that cancels such a change. Is done.

  According to a third aspect of the present invention, there is provided the electric shutter overload detection device according to the first or second aspect, wherein the current value of the load detection means is read from the load information of the load storage means in the operating state. It has a load discriminating means for collating and discriminating the load state of the DC motor.

  In the invention according to claim 3, the current value of the read load information is collated with the current value detected during operation to determine the load state.

  According to a fourth aspect of the present invention, there is provided the electric shutter overload detection device according to the third aspect of the invention, wherein the load determining means is from the lower limit position to the upper limit position in the winding state or from the upper limit position to the lower limit position in the lowering state. In any of the positions, the current value of the load detection means deviates from the current value of the load storage means to the outside of the set range, and the overload state is assumed.

  In the invention according to claim 4, although the drive current changes with winding and lowering, and the overload state varies due to various obstacles, the current value is at each position during operation. It is corrected appropriately by setting a predetermined range in and monitoring.

  According to a fifth aspect of the present invention, there is provided the electric shutter overload detection device according to any one of the first to fourth aspects, wherein the load storage means periodically stores the stored load information for each set period. In addition, it is characterized in that it is updated spontaneously with new load information during a period not overloaded.

  In the fifth aspect of the invention, since the reference load information is continuously updated within the set period, the secular change of the control system including the DC motor and the control circuit is eliminated. As such an update process, there is a process based on the premise that load information in an overload state is excluded.

  According to the apparatus of claim 1, in the shutter device using the electric motor, the DC motor is controlled at a constant speed, the correction table of the driving voltage and frequency can be reduced, and the load information of the measured current value is obtained. Useful and detailed detection is possible. Therefore, it is possible to provide an electric shutter overload detection device that can reliably and inexpensively detect an overload state of an electric motor by simple control.

  According to the device of the second aspect, the same effect as that of the first aspect of the invention can be obtained, and the rotational speed can be stably controlled by complementing the magnetization characteristics of the DC motor. By detecting the operating temperature as the ambient temperature, it is possible to correct the load of the shutter main body that changes depending on the temperature, and to perform reliable detection processing.

  According to the third aspect of the present invention, it is possible to obtain the same effect as that of the first or second aspect of the invention. Can be guaranteed.

  According to the apparatus described in claim 4, the same effects as those of the invention described in claim 3 can be obtained. Detailed and reliable discrimination is possible.

  According to the device of the fifth aspect, it is possible to obtain the same effect as the invention according to any one of the first to fourth aspects, as well as the predetermined regardless of the secular change of the DC motor. Detection accuracy can be maintained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram for explaining an electric shutter overload detection device according to an embodiment of the present invention, in which a new winding drum of an electric shutter device to which the detection device is applied is partially cut away. It is sectional drawing shown. In addition, each part similar to a prior art example is shown with the same code | symbol, and detailed description of these each part is abbreviate | omitted.
This electric shutter device is a new winding drum 40 in which a DC motor 20 and a brake device 30 are incorporated in place of the electric motor 93, the driving device 94 and the winding drum 95 in the electric shutter device 9 of the conventional example shown in FIG. And a control device 10 such as a DC motor 20 is provided in a storage BOX 50 provided in the upper part. The new winding drum 40 shown in FIG. 1 has a cylindrical shape that is tilted horizontally, has one end opened, and the DC motor 20 is inserted in the direction of the rotating shaft 21 up to the support wall 42 in the central portion. Since the shaft 21 and the support wall 42 are fixed, the DC motor 20 rotates the winding drum 40 through a built-in speed reducer 45 or the like. In addition, a balance spring 31 is provided at the other end so as to face the support wall 42 and balance the slat load.

  The direct current motor 20 includes an encoder, and a brake device 30 is continuously provided with the rotary shaft 21 in the same manner. The thermistor 22a and the hall element (position detecting means) 22b are embedded in the encoder and the like, and the cables of the control device 10 are wired to the thermistor 22a, the hall element 22b, the DC motor 20, the brake device 30, and the like. . The DC motor 20 is a DC brushless motor, and detects the heat generation temperature and ambient temperature of the stator and the like by the thermistor 22a, and detects one rotation of the rotor by the Hall element 22b. Instead of such a DC brushless motor 20, a motor with a DC brush may be used. In that case, an encoder may be provided in the DC motor 20 in place of the Hall element 22b to detect the rotational speed. In the electric shutter device improved in this way, an upward force is applied to the shutter curtain by the balance spring 31 in order to easily roll up the shutter curtain against its own weight. As a result, the rotational force of the DC motor 20 is configured to approximate the rotational force in the lowered state when in the wound state.

FIG. 2 is a block diagram for explaining a schematic configuration example of the control device shown in FIG.
The control device 10 shown in FIG. 1 has a constant speed control unit (constant speed control means) 11 that controls the rotational speed of the DC motor 20 to a constant speed, and a potential difference between the drive current of the DC motor 20 such as a detection resistor. A current conversion circuit 12 that converts the resistance value of the thermistor 22a into a voltage signal, a brake driver 14 that drives the brake device, the constant speed control unit 11, the current conversion circuit 12, and resistance conversion A microcomputer system (hereinafter abbreviated as a microcomputer) 15 to which the circuit 13, the brake driver 14, and the hall element 22b circuit are connected, and an operation unit 16 for the microcomputer 15 are provided. The constant speed control unit 11 includes an FET bridge 111 that supplies a three-phase drive current to each coil in order to perform PWM (Pulse width modulation) control of the DC motor 20, and a signal conversion unit 112 that detects a pulse signal from the DC motor 20. And a motor driver 113 serving as an interface between the microcomputer 15 and a control system such as the FET bridge 111, the DC motor 20, and the signal conversion unit 112. That is, a predetermined rotational speed is maintained regardless of load fluctuations by PWM control that changes the ON / OFF duty cycle of the DC motor 20. The Hall element 22b circuit detects the home position signal of the DC motor 20.

  The FET bridge 111 is, for example, a three-phase bridge circuit in the case of a brushless motor and an H-shaped bridge circuit in the case of a brushed motor. The current conversion circuit (load detection means) 12 inputs the combined current value of the FET bridge 111 to the load signal terminal of the microcomputer 15 as a potential difference of a detection resistor or the like, but after detecting the current value of each phase. Even if they are combined, they may be introduced into the microcomputer 15 as three independent signals and then combined, or the digital values may be added together in the microcomputer 15. The operation unit 16 has an operation panel on which various switches, LEDs 162 and a photocoupler 163 are arranged and connected to the microcomputer 15. The input signal of the LED 162 is supplied through the LED driver 164 of the control device 10. The microcomputer 15 includes a system timer oscillator 15a, a ROM 15b such as a control program, a memory 15c such as control data, and a microprocessor. The memory 15c is preferably an EEPROM (Electrically Erasable Programmable Read-Only Memory) element, but may be a memory element that can hold data while the power is shut off or has a battery backup function.

3 is a block diagram for explaining a schematic configuration example of the electric shutter overload detection device of the microcomputer shown in FIG.
This overload detection device is configured as a microcomputer 15 function, and includes a device drive function (constant speed control means) 151 for exchanging a control signal for PWM control and the like with the constant speed control unit 11, signal processing of the device drive function 151, and the like. Therefore, a temperature correction function (temperature correction means) 152 for setting a temperature correction value, a position detection function (position detection means) 153 for counting the number of rotations of the DC motor 20, and signal processing of the device drive function 151, etc. Therefore, the load detection function (load detection means) 154 for measuring the current value of the drive current, the measured current value and the temperature correction value are sequentially associated with the counted number of rotations (position information), and the moving average value is sequentially And a load record (load information) group in which each moving average value is associated with the number of revolutions is stored in the memory 15c. Both load storage function (load storage means) 156 provided corresponding to the rotation speed, state switching function 157 for switching the load storage function 155 and the like to the setting / operation state, and the current value measured in the operation state are the load A load discriminating function (load discriminating means) 158 that causes the constant speed control unit 11 to perform an overload process when the current value of the record deviates is provided.

  In the apparatus drive function 151, a timer signal such as a system, a forward / reverse signal, a PWM signal, a stop signal, and the like are issued as control signals, and control data such as a rotation speed that becomes a target value is formed. The temperature correction function 152 is programmed with a temperature correction formula with a predetermined correction coefficient. However, if there is a margin in memory space, a correction table may be used. In addition, for example, 18 pulses are set as the number of rotation pulses (home position signal) for one rotation in the position detection function 153 (the detection accuracy varies greatly with 2 pulses, and the memory space is consumed when 36 pulses or more. ), The current value conversion coefficient is set in the load detection function 154. In the averaging function 155, calculation timing (for example, every rotation / pulse), a population size (for example, four rotations), a determination range register 155a, and the like are set. The state switching function 156 is provided with a load record group spontaneous update function. For this spontaneous update function, an update cycle, an update schedule, a start event (for example, during steady operation that is not in an overload state), etc. are set. Yes.

  By using the moving average value as a reference in this way, for example, instantaneous load fluctuations due to unexpected noise can be absorbed, and by providing a judgment range, only overload conditions due to obstacles etc. can be detected reliably. In addition, the spontaneous update function can cope with aging of the entire control system including the DC motor 20 and the mechanism, and as a result, stable overload detection can be guaranteed. The load record is obtained by adding a determination range (setting range) to the current value. Instead of the register 155a of such a determination range, another register is provided in the load determination function 157 so that the value of the record You may restrict | limit the magnitude | size of. In addition, the load storage function 156 is simply provided with a sequential access function, but an index such as an upper limit / lower limit position, an activation / braking period may be provided to facilitate the search.

Next, an example of the electric shutter device overload detection method according to the embodiment of the present invention will be described. First, an example of a software process will be described with reference to an example of a flowchart shown in FIGS. 4A and 4B and each diagram shown in FIGS.
As a preparation, after completion inspection of each part of the shutter device and confirming that there are no obstacles, the state switching function 156 is switched to the “set state”. When the operator turns on the “open shutter curtain” switch, the device drive function 151 instructs a winding state by a “forward command” to wind up the shutter curtain. Further, the electric shutter device is activated while controlling the rotational speed of the DC motor 20 to a constant speed based on the temperature correction value of the temperature detection function 152 and other control data (step ST1). When an excessive load is generated in the mechanical unit at the time of starting, for example, the device driving function 151 is soft-started so as to keep the speed lower than the speed in the steady state, or the load detecting function 154 is set to the starting period. It may be configured to block only. The braking period at the upper limit position or the like can be similarly processed.

FIG. 5 is a diagram for schematically explaining the moving average value of the averaging function shown in FIG. 4A and FIG. 4B, showing the set state in the upper part of the drawing and contrasting the operation state in the lower part. It is.
Next, the position detection function 153 sends each position from the lower limit position to the upper limit position in the winding state to the averaging function 155 as position information for each rotation (step ST2). In synchronization with this, the load detection function 154 converts the drive currents A1, A2,... An of the DC motor 20 for each pulse, and sends n (18 in this figure) pulses to the averaging function 155. (Step ST3). With the averaging function 156, each current value of 4 rotations (total 72 pulses) with the past 3 rotations (too sensitive for 3 rotations or less, response decreases for 5 rotations or more) is a moving average equivalent to 1 pulse. A reference value obtained by adding the determination range to the value B1 is sent to the load storage function 156 every rotation (step ST4). The reference value is associated with the position information to form a load information record, and is stored in the load storage function 156 (step ST5). Also, in the case of lowering, another determination range for lowering (simply the same range as winding) is set in the register 155a, and averaging is similarly performed for each position from the upper limit position to the lower limit position. Accumulate each reference value by function. The above settings are initially set before normal operation, and these settings are automatically performed.

6 is a graph for schematically explaining an overload state of the load determination function shown in FIGS. 6 and 4B together with a transition of a moving average value or the like.
In normal operation, a determination range in which an obstacle can be specified is set in the register 155a in advance using the operation unit 16 or the like, and the state switching function 156 is switched to the “operation state”. Even in this operating state, when the “open shutter curtain” switch is turned on, the device drive function 151 similarly activates the electric shutter device while controlling the rotational speed of the DC motor 20 to a constant speed (step ST1). Since load information corresponding to position information is stored as a reference value in the load storage function 156, the determination reference drive current B1 is read from this load information (step ST6). Similarly, the drive currents a1, a2,... An of the load detection function 154 are detected by performing the processes (steps ST2 to ST5), and the moving average values b1, b2,. Is compared with the drive current B1 for each pulse to determine whether or not it is in an overload state (step ST7). If the drive currents a1, a2,... An are within the determination range, the detection of the next rotation pulse is repeatedly executed until the determination as to whether or not an overload condition is reached reaches the upper limit position (or braking period). If it is outside the determination range, the device drive function 151 is warned and an overload process is executed. For example, the brake driver 14 is immediately issued to issue a brake signal to activate the brake device 30. (Step ST8). A predetermined end process is executed following the above processes.

  Also in the case of lowering, when another determination range for lowering (simply the same range as that of winding) is set in the register 155a and the “shutter curtain closing” switch is turned on, the shutter curtain is lowered. The electric shutter device is activated by a “reverse command” or the like (step ST1). Thereafter, steps ST6, 2-5, 7, and 8 are executed for the lowering position from the upper limit position to the lower limit position, and the process ends. Thus, overload detection is performed safely and appropriately from the upper limit value to the lower limit value of the shutter curtain in winding and lowering. In the overload processing at this time, for example, a reverse signal is immediately issued to the DC motor 20 and reverse PWM control is performed. Alternatively, the brake device 30 can be configured to operate.

FIG. 7 is a flowchart for explaining a process example of the device driving function shown in FIG.
In this function, control data related to the duty cycle is preset in the memory 15c and the like. First, in the DC motor 20, the home position signal is detected from the Hall element 22b based on the current duty cycle, and the pulse interval is measured (step ST21). Further, the control data of the duty cycle corresponding to the target rotation speed is referred to and compared with the pulse interval (step ST22). By determining whether or not the difference is within the management range, the duty cycle is maintained when the difference is within the management range (step ST23). If the difference is outside the management range, a new duty is determined based on the control data. Change to a cycle (step ST24). By continuously repeating these processes (steps ST21 to ST24) in sequence, the target rotational speed is maintained in the DC motor 20. That is, when the DC motor 20 is likely to decelerate due to an obstacle or the like, an overload state that increases the drive current is formed.

  In general, control tables for AC motors and the like need correction tables for fluctuations in drive voltage, frequency, etc., but these correction tables become unnecessary by controlling the DC motor 20 at a constant speed in this way. No more consuming valuable memory space. Since the load applied to the DC motor 20 is proportional to the drive current in this way, the load state can be directly detected from the drive current, for example, through an analog input terminal of the microcomputer. These merits are combined with simplification of microprograms, and a simple configuration can be realized by, for example, a microsequencer. These are only examples, and the overload state can be determined even if the same state is determined when two pulses are continuously determined, and the comparison of the current value is set as long as it is synchronized with the home position signal. You may make it the structure made to carry out discretely for every distance or setting period.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the schematic structural example of the electric shutter overload detection apparatus which concerns on embodiment of this invention, Comprising: The new winding drum of the electric shutter apparatus with which this detection apparatus is applied is notched partially It is sectional drawing shown. 2 is a block diagram for explaining a schematic configuration example of the control device shown in FIG. 3 is a block diagram for explaining a schematic configuration example of the electric shutter overload detection device of the microcomputer shown in FIG. It is a figure which shows the process example of the electric shutter apparatus overload detection method which concerns on embodiment of this invention, and is a flowchart which shows an example in a setting state as a process in software. It is a flowchart which shows an example in an operation state similarly. It is a figure for demonstrating typically the moving average value of the averaging function shown to FIG. 4A and FIG. 4B. 4B is a graph for schematically explaining an overload state of the load determination function shown in FIG. 4B. 4 is a flowchart for explaining a process example of a device driving function shown in FIG. 3. It is a perspective view for demonstrating the electric shutter apparatus etc. which concern on a prior art example.

Explanation of symbols

12 Current conversion circuit (load detection means)
13 resistance conversion circuit 15 microcomputer 22b hall element circuit (position detection means)
113 Motor driver (constant speed control means)
151 Device drive function (constant speed control means)
152 Temperature correction function 153 Position detection function (position detection means)
154 Load detection function (load detection means)
155 Averaging function 155a Register 156 Load storage function (load storage means)
157 State switching function 158 Load discrimination function (load discrimination means)

Claims (5)

Electric shutter overload that detects an overload condition that prevents the winding and lowering from being hindered in an electric shutter device that uses a DC motor to wind up the shutter curtain to form an opening and to close the opening by lowering the shutter curtain A detection device,
Constant speed control means for controlling the rotational speed to a constant speed even if a factor that can vary the rotational speed of the DC motor occurs,
Position detecting means for knitting position information relating to the winding position or lowering position of the shutter curtain by detecting the rotational speed of the DC motor;
Load detecting means for organizing load information related to the load state of the DC motor by detecting the current value of the drive current;
The load information is stored in association with the position information, and the load information corresponding to the stored position information is referred to in the operating state of the electric shutter device. Electric shutter overload detection device.   The electric shutter overload detection device according to claim 1, wherein the constant speed control unit corrects the drive current in accordance with a detected temperature of the DC motor.   2. A load discriminating unit for determining a load state of a DC motor by reading a current value from load information of a load storage unit and collating it with an electric current value of a load detecting unit in an operation state. Alternatively, the electric shutter overload detection device according to claim 2.   The load determining means sets the current value of the load storage means to the current value of the load storage means at any position from the lower limit position to the upper limit position in the winding state or from the upper limit position to the lower limit position in the lowered state. The electric shutter overload detection device according to claim 3, wherein the overload state is determined by deviating to the outside.   2. The load storage unit spontaneously updates the stored load information regularly, every set period, or in a period not overloaded, with new load information. The electric shutter overload detection device according to claim 4.

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