JPH0543191Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a safety device for motor control of electric shutters such as electric shutters installed at the entrances and exits of buildings.

[Prior art and problems to be solved by the invention] Generally, in this type of motor, if it is an electric shutter, the electric motor is driven and controlled by pressing a push button switch to open/close and stop the shutter curtain. It's becoming like that. and,
The control circuit mechanism that controls these drives is composed of an operation side circuit that instructs raising and lowering and an operation side circuit that drives the electric motor M, and a relay switch provided in the operation side circuit.
RYU, RYD, up, down push button switch PBU,
By turning on each PBD, the switches are switched and actuated to control the drive of the operating circuit.

However, in the relay switches RYU and RYD, if an overcurrent flows for some reason, the contacts may become welded and the switch contacts may remain closed, resulting in an uncontrollable state. In such a case, even if the push button switch is pressed to open/close the limit switch LSU or LSD or emergency stop in the operating circuit, the operating circuit will not be disconnected and the lifting operation will continue, which may cause the lifting operation to continue. If this occurs, it may damage the magnifying section or cause burnout of the motor, and if it is descending, it may cause serious problems such as reverse winding.For this reason, the contacts of the relay switch may be welded. It is strongly desired to provide a means to open the circuit on the active side by some method when this occurs.

[Means for Solving the Problem] In view of the above-mentioned circumstances, the present invention was devised for the purpose of providing a safety device for motor control that can eliminate these drawbacks. The control circuit includes a drive detection means for detecting whether the motor is driving or not, and the control circuit for controlling forward and reverse drive of the motor includes a control circuit for detecting whether the control circuit is in an uncontrollable state. In addition to providing a failure detection means for each, signals from both detection means are input, and a detection signal indicating that the motor is driving but the control circuit is in an uncontrollable state is determined to be an abnormal state and an emergency stop is performed. The apparatus is characterized in that it is provided with an abnormality determining means that outputs a signal, and an emergency stop means that cuts off the power to the power supply circuit in response to an emergency stop signal from the abnormality determining means.

With this configuration, the present invention immediately detects if the relay switch becomes uncontrollable due to contact welding, cuts off the power to the actuating circuit, and makes an emergency stop, thereby preventing a serious problem from occurring. This is so that it can be prevented.

[Example] Next, an example of the present invention will be described based on the drawings. In the drawing, reference numeral 1 denotes an electric shutter, and the electric shutter 1 opens and closes the opening by vertically moving up and down while guiding the shutter curtain 3 to the guide rail 4 by the forward and reverse driving of the opening/closing device 2. FIG. 2 shows a circuit diagram of the lift control circuit mechanism. Here, R, S, and T are each phase of the three-phase AC power supply, and M
is the motor, B is the brake, E is the power supply, KS is the main switch, F is the fuse, PBU, PBD, and PBS are push button switches for raising, lowering, and stopping, respectively, EMS is the emergency stop switch, LSU, LSD
are limit switches for upper and lower limits, respectively, and RYU and RYD are relay switches and their switch contacts for raising and lowering, respectively, and these are all wired in conventional circuits.

This drive control circuit mechanism runs from a power source E to a motor M.
It is comprised of a power supply circuit leading to the motor M, and a control circuit that issues control commands for driving the motor M in forward and reverse directions. In the embodiment of the present invention, each relay switch on the control circuit side
Raising and lowering operation detection units 5a and 5b each consisting of a photodiode and a phototransistor are provided between terminals B ₂ and L ₁ and B ₄ and L ₂ on both sides of RYU and RYD, respectively, and the control circuit is in a energized state. When the detection light is on, the photodiode transmits detection light to the phototransistor, and the phototransistor receives this and outputs an output signal "1" to the NOR circuit (judgment section) 6. The NOR circuit 6 determines when all of the control circuits are open and the output signals from the ascending and descending operation detecting sections 5a and 5b are "0", and sends a signal to the AND circuit. It is designed to output "1" and constitutes the uncontrollable detection means of the present invention.

On the other hand, terminals U and W of the R phase and T phase of the power supply circuit
A drive detecting means 5c composed of a photodiode and a phototransistor is provided between the phototransistor and the phototransistor. It is configured to receive the signal and output the signal "1" to the AND circuit 7, forming the abnormality determining means of the present invention.

Further, the AND circuit 7 is configured to receive signals from the drive detection means 5c and the NOR circuit 6 as described above, but when both of these input signals are "1", the control If the circuit side is in an open state but the power supply circuit side is in a closed state, it is determined as an abnormality and an emergency stop signal is sent to the emergency stop circuit 8 side, thereby forming an abnormality determining means. There is. Then, this emergency stop signal flows as a base current of the transistor Tr of the emergency stop circuit 8, and thereby the emergency stop circuit 8 is closed, and the emergency stop relay RE is energized, and the relay contact RE provided in the power supply circuit is energized. When the relay contact RE installed on the control circuit side is opened, the power to the motor N is cut off.
When the alarm 9 is closed, the alarm 9 is activated.

In the embodiment of the present invention configured as described above, for example, if the switch contact RYD of the lowering relay is welded for some reason and remains closed during the lowering operation of the shutter curtain 3, the shutter curtain Even if the lower limit switch LSD is opened and the control circuit becomes open circuit when the lower limit switch LSD is opened, the motor M tries to continue operating. However, in this case, in the device in which the present invention is implemented, the output signals from the ascending and descending operation detection means 5a and 5b are both "0", and as a result, the NOR circuit 6 that has determined this outputs "1". The output signal will be sent to the AND circuit 7. On the other hand, in the power supply circuit, the switch contact RYD is welded and remains in the closed state, and the motor M continues to be driven. Therefore, the drive detection means 5c detecting this, outputs a detection signal of "1" to the AND circuit. 7 will be output. The AND circuit 7 is connected to the NOR circuit 6 and the drive detection means 5.
If the signals from C and C are all "1", this is determined to be abnormal and an emergency stop signal is sent to the emergency stop circuit 8, and as a result, the emergency stop circuit 8 energizes the emergency stop relay RE. In the power supply circuit, the switch contact RE is opened to cut off the power and the motor M is brought to an emergency stop, while in the control circuit, the switch contact RE is closed to issue an alarm and notify of an abnormality.

In the case where the present invention is implemented in this way, if the contacts of the ascending and descending relays RYU and RYD become welded for some reason, the power supply circuit will not work even though the control circuit is open. closed state,
That is, if the motor M attempts to continue driving, this is detected and the power to the motor M is cut off to perform an emergency stop. As a result, various problems caused by the continued driving of the motor M can be prevented. , it can be made extremely safe and reliable. Moreover, in the embodiment, an alarm can be issued to notify of abnormality, so that repairs or other measures can be taken immediately.

In addition, this safety device is a simple device that can be installed within the power distribution board, and is therefore inexpensive and can be easily added to shutter devices that are not equipped with conventional safety devices. It is.

The present invention is not limited to the above-mentioned embodiments, and can be used in various applications as long as it controls the forward and reverse drive of a motor, and is not limited to electric opening/closing machines such as automatic doors. The present invention can also be applied to devices that use a motor to control vertical movement, such as those that use a motor.

[Operations and Effects] In short, the present invention is configured as described above, so it is possible to prevent abnormalities such as contact welding, etc., in which the motor continues to drive even though the control circuit is in a stop control state. When the abnormal state occurs, the abnormality determining means determines that the abnormal state is present based on the input of the detection signal from each corresponding detection means provided in both circuits, and issues an emergency stop signal to the emergency stop means. Extremely safe motor drive control that can reliably prevent serious problems such as the motor stopping and causing burnout or damage to actuated parts due to the motor not stopping. It is something that can be done.

[Brief explanation of the drawing]

The drawings show an embodiment of the motor control safety device according to the present invention, in which FIG. 1 is a schematic diagram of the shutter, FIG. 2 is a diagram of the mechanism of the elevator control circuit, and FIG. 3 is a block diagram. In the figure, 1 is a shutter, 3 is a shutter curtain, 5a is a rising operation detection section, 5b is a descending operation detection section, 5c is a drive detection means, 6 is a NOR circuit, 7 is an AND circuit, 8 is an emergency stop circuit, 9 is an alarm, RE
is the emergency stop relay and its switch contact.

Claims (1)

[Scope of utility model registration request] The power supply circuit for the motor includes a drive detection means for detecting whether or not the motor is being driven, and the control circuit for controlling the forward and reverse drive of the motor has a means for detecting whether the control circuit is in an uncontrollable state. In addition to providing uncontrollable detection means for detecting whether the A motor control system comprising: an abnormality determining means for determining the abnormality and outputting an emergency stop signal; and an emergency stop means for cutting off the power to the power supply circuit in response to the emergency stop signal from the abnormality determining means. Safety device.