JP5220126B2 - Elevator safety circuit device - Google Patents

Description

  The present invention relates to an elevator safety circuit device having a safety circuit that detects an abnormal state when a safety switch is opened and generates a car stop command to a brake device.

  In a conventional elevator control device, a switch having the same configuration as the lower limit switch is also provided on the first floor from the lowest floor. When the pit is flooded, the limit switch to be applied is switched, thereby preventing the service degradation of the elevator when the pit is flooded (see, for example, Patent Document 1).

JP-A-5-32382

  In the conventional elevator control apparatus as described above, it is necessary to switch a part of the safety circuit in order to switch the limit switch to be applied, and there is a possibility that the service is deteriorated due to the operation of the safety circuit due to the switching operation.

  The present invention has been made in order to solve the above-described problems, and is an elevator safety capable of operating an elevator without suddenly stopping the car when a safety switch failure is detected. An object is to obtain a circuit device.

The elevator safety circuit device according to the present invention includes at least one first safety switch, and detects the abnormal state when the first safety switch is opened to generate a car stop command to the brake device. A second safety switch including a circuit, at least one second safety switch, and detecting an abnormal state similar to that of the first safety circuit and generating a car stop command to the brake device when the second safety switch is opened A failure detection unit that detects a failure release in which the first safety switch is opened due to a failure based on the state of the circuit, the first and second safety switches, and the first safety circuit is normally connected to the brake device The second safety circuit is disconnected from the brake device, and when the failure detection unit detects the failure release, the circuit connected to the brake device is connected to the first safety circuit. A switching device for switching from the entire circuit to the second safety circuit is provided, and the circuit switching time by the switching device is shorter than the time from when the first safety switch is opened until the braking operation of the brake device is started. Is set.
The elevator safety circuit device according to the present invention includes at least one first safety switch, and detects the abnormal state when the first safety switch is opened to generate a car stop command for the brake device. The safety circuit includes at least one second safety switch. When the second safety switch is opened, an abnormal state similar to that of the first safety circuit is detected and a car stop command is issued to the brake device. Safety circuit, a failure detection unit that detects a failure release in which the first safety switch is opened due to a failure based on the states of the first and second safety switches, and the first safety circuit in a normal state as a brake device And the second safety circuit is disconnected from the brake device, and when the failure detection is detected by the failure detection unit, the circuit connected to the brake device is A switching device for switching from one safety circuit to a second safety circuit, and when the failure detection unit detects a failure release, the switching device connects the second safety circuit to the brake device, and then the first safety circuit. Disconnect the circuit from the braking device.

It is a block diagram which shows the elevator by Embodiment 1 of this invention. It is a circuit diagram which shows the safety circuit apparatus of the elevator of FIG. 3 is a timing chart showing the operation of the brake contactor when the circuit switching time by the switching device of FIG. 2 is longer than the time required for the brake coil current to be cut off by the brake contactor. 3 is a timing chart showing the operation of the brake contactor when the circuit switching time by the switching device of FIG. 2 is shorter than the time required for the brake coil current to be cut off by the brake contactor. It is a timing chart which shows the circuit switching operation | movement of the safety circuit apparatus of the elevator by Embodiment 2 of this invention.

Preferred embodiments of the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing an elevator according to Embodiment 1 of the present invention. In the figure, the car 1 and the counterweight 2 are suspended in the hoistway by the suspension means 3 and are raised and lowered in the hoistway by the driving force of the hoisting machine 4. As the suspension means 3, a plurality of ropes or a plurality of belts are used.

  The hoisting machine 4 has a drive sheave 5 around which the suspension means 3 is wound, a hoisting machine motor 6 as a driving device that rotates the driving sheave 5, and a brake device 7 that brakes the rotation of the driving sheave 5. doing. The brake device 7 includes a brake drum 8 that is coaxially coupled to the drive sheave 5, a brake shoe 9 that is in contact with and separated from the brake drum 8, and a brake spring that presses the brake shoe 9 against the brake drum 8 and applies a braking force (see FIG. And an electromagnetic magnet (not shown) for releasing the braking force by pulling the brake shoe 9 away from the brake drum 8 against the brake spring.

  An upper pulley 10 is provided at the upper part of the hoistway. A lower pulley 11 is provided at the lower part of the hoistway. A governor rope 12 is wound around the upper pulley 10 and the lower pulley 11. Both ends of the governor rope 12 are connected to the car 1. The governor rope 12 is circulated as the car 1 moves up and down. Thereby, the upper pulley 10 is rotated at a speed corresponding to the traveling speed of the car 1. The upper pulley 10 is provided with a governor encoder 13 that generates a signal corresponding to the rotational speed of the upper pulley 10.

  The hoist motor 6 and the brake device 7 are controlled by the operation control device 14. That is, the operation of the car 1 is controlled by the operation control device 14. The operation control device 14 controls the hoist motor 6 to move the car 1 up and down, and keeps the car 1 stationary by the brake device 7 on the target floor. Further, the operation control device 14 has a microcomputer in which a program for operating the car 1 is stored.

  A signal from the governor encoder 13 is input to a safety control device (electronic safety controller) 15. The safety control device 15 monitors the presence or absence of an elevator abnormality independently of the operation control device 14. The safety control device 15 has a microcomputer. The microcomputer of the safety control device 15 stores a program for controlling power supply to the hoisting machine motor 6 and the brake device 7 in accordance with the detected abnormality content. The safety control device 15 can also be configured by a logic circuit.

  FIG. 2 is a circuit diagram showing a safety circuit device of the elevator shown in FIG. The electromagnetic magnet of the brake device 7 has a brake coil 21. The safety control device 15 controls the braking force of the brake device 7 by controlling energization to the brake coil 21. For example, the safety control device 15 intermittently applies the braking force of the brake device 7 so that the deceleration of the car 1 when the car 1 is emergency-stopped is not excessive, thereby increasing the braking force of the brake device 7. Control. However, the circuit configuration for controlling the braking force is omitted in FIG.

  The brake device 7 further includes a brake contactor 22 that supplies and cuts off electric power to the brake coil 21.

  A first safety circuit (main safety circuit) 23 is connected between the brake contactor 22 and the power source. The first safety circuit 23 includes at least one first safety switch 25 connected in series.

  Further, the first safety circuit 23 detects an abnormal state when the first safety switch 25 is opened, and issues a car stop command to the brake device 7. That is, when at least one of the first safety switches 25 is opened while the car 1 is traveling, the power supply to the brake contactor 22 is cut off. As a result, the energization to the hoist motor 6 is interrupted, the energization to the brake coil 21 is interrupted, and the car 1 is suddenly stopped.

  A second safety circuit (preliminary safety circuit) 24 is provided in parallel with the first safety circuit 23 between the brake contactor 22 and the power source. The brake contactor 22 and the second safety circuit 24 are normally disconnected from each other. The second safety circuit 24 includes at least one second safety switch 26 connected in series.

  Further, the second safety circuit 24 detects an abnormal state similar to that of the first safety circuit 23 when the second safety switch 26 is opened, and issues a car stop command to the brake device 7. However, in normal times, the second safety circuit 24 is disconnected from the brake contactor 22 and is on standby, so that the car stop command is not transmitted to the brake contactor 22.

The first safety switch 25 and the corresponding second safety switch 26, that is, the second safety switch 26 with the same monitoring target, always have the same open / closed state unless they are faulty.

  Examples of the first and second safety switches 25 and 26 include an upper hoistway switch, a lower hoistway switch, a car door open detection switch, a landing door open detection switch, and an overspeed detection switch.

  Which one of the first and second safety circuits 23 and 24 is connected to the brake contactor 22 is switched by a switching device 27. The switching device 27 includes an electromagnetic relay 28 and a semiconductor switch 29 that is an electrical switch connected in series to the electromagnetic relay 28.

  The electromagnetic relay 28 is provided between the first and second safety circuits 23 and 24 and the brake contactor 22, and selectively connects the first and second safety circuits 23 and 24 to the brake contactor 22. The semiconductor switch 29 turns on and off the energization of the coil of the electromagnetic relay 28.

  On / off of the semiconductor switch 29 is controlled by the failure detection unit 30. The failure detection unit 30 detects a failure release in which the first safety switch 25 is opened due to a failure based on the states of the first and second safety switches 25 and 26. Specifically, the failure detection unit 30 compares the states of the first and second safety switches 25 and 26 that are opened in the same abnormal state (the monitoring targets are the same), and the second safety switch A state in which the first safety switch 25 is opened even though 26 is closed is detected as a failure open.

  In addition, since no current flows through the second safety circuit 24 at normal times, it is considered that an ON failure due to energization does not occur in the second safety switch 26. For this reason, the state in which the first safety switch 25 is opened and the second safety switch 26 is closed is considered to be the failure opening of the first safety switch 25.

  The failure detection unit 30 is provided in the safety control device 15. The function of the failure detection unit 30 is realized by the microcomputer or the logic circuit of the safety control device 15.

  The switching device 27 normally connects the first safety circuit 23 to the brake contactor 22 and disconnects the second safety circuit 24 from the brake contactor 22. However, when the failure detection unit 30 detects a failure release, the switching device 27 switches the circuit connected to the brake contactor 22 from the first safety circuit 23 to the second safety circuit 24.

  Further, the circuit switching time T1 between the first and second safety circuits 23 and 24 by the switching device 27 is from when the first safety switch 25 is opened until the braking operation of the brake device 7 is actually started. The time is set shorter than the time T2 (T1 <T2). Specifically, T2 is normally about 50 to 100 mmsec depending on the specification of the brake contactor 22, and T1 is set so that T1 <T2 including an error with respect to T2. The selection of the electromagnetic relay 28 for setting T1 is performed based on the estimated value of the time required for detection by the failure detection unit 30 and the operation specifications of the semiconductor switch 29.

  Next, the operation will be described. In normal times, the second safety circuit 24 is disconnected from the brake contactor 22, and the first safety circuit 23 is in an effective state. When at least one of the first safety switches 25 is opened due to some abnormality in the elevator, the energization to the hoisting motor 6 is cut off and the energization to the brake coil 21 is cut off. Is suddenly stopped.

  On the other hand, the failure detection unit 30 constantly monitors whether the first safety switch 25 is open for failure. When a failure release is detected, the semiconductor switch 29 is turned off and the electromagnetic relay 28 is de-energized so that the circuit connected to the brake contactor 22 is changed from the first safety circuit 23 to the second safety circuit. Switch to 24 instantly.

  At this time, as shown in FIG. 3, when the circuit switching time T1 by the switching device 27 is longer than the time T2 required for the brake coil current to be cut off by the brake contactor 22, the power supply to the brake contactor 22 is temporarily stopped. As a result, the car 1 is suddenly decelerated by the braking force of the brake device 7, and the car 1 is suddenly stopped depending on the length of T1.

  On the other hand, in the elevator safety circuit device according to the first embodiment, as shown in FIG. 4, by setting T1 <T2, the car can be detected even when the failure of the first safety switch 25 is detected. The elevator can be operated without suddenly stopping 1. That is, even if the operating first safety circuit 23 breaks down, the operation is switched to the second safety circuit 24 that is in a standby state, so that the car 1 can be operated safely without suddenly stopping.

  Further, the failure detection unit 30 compares the states of the first and second safety switches 25 and 26 that are opened in the case of a similar abnormal state, and the second safety switch 26 is closed even though it is closed. Since the state where the first safety switch 25 is opened is detected as a failure open, the failure of the first safety circuit 23 can be detected with high accuracy.

  Further, when an abnormality in the elevator is detected, the energization to the brake contactor 22 is cut off, and the energization to the hoisting machine motor 6 and the brake coil 21 is cut off by the mechanical switch. Can be stopped.

  Furthermore, when the failure detection unit 30 detects a failure release, the semiconductor switch 29 is turned off, so that circuit switching can be performed at high speed.

The elevator operation can be continued after switching to the second safety circuit 24, but the failure of the first safety circuit 23 is notified to the maintenance center and the car 1 is stopped at a predetermined floor. After the operation, it is preferable to stop the operation of the elevator and perform the inspection work.
In addition, after switching to the second safety circuit 24, the failure of the first safety circuit 23 is notified to the maintenance center or the like, and the second safety circuit 24 is operated only until the maintenance work is performed by the maintenance staff. You may make it drive | operate in a state.
Further, the first and second safety switches 25 and 26 may not correspond completely at 1: 1, for example, there are more second safety switches 26 than the first safety switches 25. Also good. That is, the number of monitoring targets by the second safety circuit 24 may be larger than the number of monitoring targets by the first safety circuit 23. Further, in this case, the safety control device 15 may be responsible for monitoring a part of the monitoring target at the normal time.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. The configuration of the elevator safety circuit device of the second embodiment is basically the same as that of the first embodiment. In the second embodiment, when the failure detection unit 30 detects a failure release, the switching device 27 connects the second safety circuit 24 to the brake contactor 22 as shown in FIG. The circuit 23 is disconnected from the brake contactor 22. That is, the switching device 27 switches the circuits so that both the first and second safety circuits 23 and 24 are not on standby at the same time.

  Even with such a safety circuit device, the elevator can be operated without causing the car 1 to stop suddenly even when a failure opening of the first safety switch 25 is detected.

In the above example, the brake device 7 that brakes the rotation of the drive sheave 5 and brakes the car 1 is shown. However, the present invention is not limited to this. A brake for braking (rope brake), a brake mounted on the car 1 and engaged with a guide rail to brake the car 1 (car brake) may be used.
Further, the number of brake devices is not limited to one, and a plurality of brake devices may be used.
Furthermore, in the above example, the car 1 is moved up and down by one hoisting machine 4, but an elevator using a plurality of hoisting machines may be used.

Claims (5)

A first safety circuit including at least one first safety switch, and detecting an abnormal state when the first safety switch is opened to generate a car stop command to the brake device;
A second safety switch including at least one second safety switch, wherein the second safety switch is opened to detect an abnormal state similar to that of the first safety circuit and generate a car stop command to the brake device; Safety circuit,
A failure detecting unit for detecting a failure release in which the first safety switch is opened due to a failure based on a state of the first and second safety switches; and, normally, the first safety circuit is connected to the brake device. And disconnecting the second safety circuit from the brake device, and detecting a failure release by the failure detector, the circuit connected to the brake device is connected from the first safety circuit to the second device. With a switching device to switch to the safety circuit,
The circuit switching time by the switching device is an elevator safety circuit device that is set to be shorter than the time from when the first safety switch is opened until the braking operation of the brake device is started.   The failure detection unit compares the states of the first and second safety switches that are opened in a similar abnormal state, and the first safety switch is closed despite the second safety switch being closed. The elevator safety circuit device according to claim 1, wherein a state in which the safety switch is opened is detected as a failure open. The first and second safety circuits are connected in parallel between the brake device and a power source,
The switching device includes a changeover switch portion that is provided between the first and second safety circuits and the brake device and selectively connects the first and second safety circuits to the brake device. The elevator safety circuit device according to claim 1. The switching device includes an electromagnetic relay that selectively connects the first and second safety circuits to the brake device, and an electrical switch that turns on and off the coil of the electromagnetic relay,
The elevator safety circuit device according to claim 1, wherein on / off of the electrical switch is controlled by the failure detection unit. A first safety circuit including at least one first safety switch, and detecting an abnormal state when the first safety switch is opened to generate a car stop command to the brake device;
A second safety switch including at least one second safety switch, wherein the second safety switch is opened to detect an abnormal state similar to that of the first safety circuit and generate a car stop command to the brake device; Safety circuit,
A failure detecting unit for detecting a failure release in which the first safety switch is opened due to a failure based on a state of the first and second safety switches; and, normally, the first safety circuit is connected to the brake device. And disconnecting the second safety circuit from the brake device, and detecting a failure release by the failure detector, the circuit connected to the brake device is connected from the first safety circuit to the second device. With a switching device to switch to the safety circuit,
When the failure detecting unit detects a failure release, the switching device connects the second safety circuit to the brake device, and then disconnects the first safety circuit from the brake device. .

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