JP2004345751A - Safety device for elevator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple brake failure detection device unnecessary for troublesome installation and adjustment. <P>SOLUTION: This elevator, keeps stopping of an elevator cage with a brake device for restraining an electric motor for driving the cage by driving the motor through a torque control means for transmitting a torque command to the motor and a current command means on the downstream side, is provided with a load detection device which detects a load in the elevator cage and inputs the information of the load in the cage to the torque control means, and a brake failure detection means for detecting failure in the brake device by comparing an output signal of the load detection system with an output signal of the current command means under a predetermined condition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an elevator safety device, and more particularly to an improvement in an abnormality detection device in an elevator brake device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an elevator is provided with a switch that accurately detects the movement of a plunger in a brake device, and detects an abnormality in the brake device by checking the movement of the plunger.
[0003]
However, in this case, it is necessary to accurately detect the movement of the plunger, and sufficient attention must be paid to the mounting and adjustment of the detection switch.
[0004]
For this reason, an apparatus shown in FIG. 3 has been proposed. (See Patent Document 1)
[0005]
[Patent Document 1]
Japanese Patent Publication No. 7-5251
That is, when the difference between the maximum value TMAX and the minimum value TMIN of the torque command 22a in the constant traveling of the elevator car becomes equal to or smaller than a predetermined value, it is possible to detect a failure in releasing the brake on the electric motor, that is, a failure in releasing the brake. This can eliminate the need for a switch for detecting a signal and wiring for the switch. The device configuration in this case is, for example, as shown in FIG. 3. The speed command 21 a of the speed command device 21 and the car speed 27 a are associated with each other to generate a torque command 22 a by the torque control unit 22, and through the current command unit 23. In an elevator system that issues a current command to the inverter, the torque command 22a of the torque command means 22 is checked, and the brake abnormality detection means 29 detects an abnormality of the brake device.
[0007]
Here, FIG. 4 shows the relationship between the car speed and the torque command when the ascending operation is performed while the brake is operated. When the torque at the time of the rated load ascending operation is set to 100%, usually 200 to 250% Since the maximum torque is required, the torque control means 22 does not operate during normal operation, but is provided with a limiter for the torque command 22a so as not to output more torque than necessary. And the brake torque of the elevator is usually about 200%. If you drive with the brakes pulled, the electric motor must generate not only the torque for driving the car but also the torque for overcoming the brake torque. Not so, resulting in considerably higher torque. For this reason, in the torque command 22a at the time of the full load increase operation, the limiter is applied over the entire region as shown in FIG. 4B, so that the torque difference ΔT = T _MAX −T _MIN is a very small value. It becomes. On the other hand, during the balanced parallel load increasing operation, the torque difference ΔT becomes smaller than the normal value as shown in FIG. Then, during the no-load ascent operation, there is no much difference from the normal state as shown in FIG.
[0008]
[Problems to be solved by the invention]
Accordingly, in monitoring such a torque difference, an abnormality cannot be detected during a no-load increase operation or a rated load decrease operation, even if the operation is performed with the brake being dragged. There was a problem that it was possible to detect an abnormality comprehensively together with other operation modes, and it was not possible to detect it early.
[0009]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an elevator safety device that can immediately detect an abnormality in a brake.
[0010]
[Means for Solving the Problems]
The present invention relates to an elevator for driving an electric motor for driving an elevator car, a torque control means for issuing a torque command to the electric motor, and an electric motor for driving the electric motor through a current instruction means at a subsequent stage to maintain the stop of the elevator car by a brake device for restraining the electric motor. A load detecting means for detecting an unbalanced load of the elevator and inputting the unbalanced load information to the torque control means, and under a predetermined condition, an output signal of the load detecting means and an output signal of the current command means. And a brake abnormality detecting means for detecting abnormality of the brake device.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention detects a brake abnormality at an early stage by checking a signal output from a current command unit.
[0012]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing a relationship between a car speed and a current command.
[0013]
3, the same reference numerals as those in FIG. 3 denote the same components, but reference numeral 30 denotes a load detecting device for detecting the load in the elevator car. This output signal is inputted to the torque control means, and the load information at that time is obtained. Start compensation is performed based on the torque command corresponding to. 31 is a brake abnormality detecting means according to the present invention, by comparing the output signal 23a from the output signal _{30a (30a 1, 30a 2,} 30a 3 ...) and the current command means 23 from the load detection device 30, the brake This is to detect abnormalities in the data. The point of time for this comparison is, for example, when the elevator car is started, when traveling at a constant speed, or immediately before stopping.
[0014]
As shown in FIG. 2, the output signal 30a of the load detecting device 30 is outputted, 30a ₁ in the case of rated load (rated load), 30a ₂ in the case of equilibrium load (balanced load), in the case of no-load weight 30a ₃ Since the signals are different in level from each other, only the current command 23a (a value smaller than the signal 30a) corresponding to this level is output in the normal state when the car is started, when the car is running at a constant speed, and immediately before stopping. By comparing the output signal 30a of the load detection device 30 with the output signal 23a of the current command means 23, it is possible to detect an abnormality very quickly. That is, if it exceeds the level of the current command 23a is the signal _{30a (30a 1, 30a 2,} 30a 3, ...), and immediately determines that the braking device is abnormal.
[0015]
Note that here an example is described in which a load detection device that detects the load in the car is adopted, but not only the load imposed on the elevator car but also the imbalance including the main ropes based on the car position is considered. Then, by detecting the car position, the abnormality of the brake may be determined based on the torque command including the overall unbalance compensation.
[0016]
A current (torque) command corresponding to the unbalanced load of the elevator is issued from the current command means 23 when the elevator car is started, when the vehicle is traveling at a constant speed, and immediately before the stop, so that a command at a different level is output. Is immediately detected by the brake abnormality detecting means 31. It is needless to say that the elevator operation is stopped after the detection.
[0017]
【The invention's effect】
As described above, according to the present invention, the brake device is appropriately checked according to the case where the elevator car is operated under various conditions, so that an abnormality can be detected very quickly. is there.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing one embodiment of the present invention.
FIG. 2 is a diagram showing a relationship between a car speed and a current command according to the apparatus of the present invention.
FIG. 3 is an overall configuration diagram showing a conventional abnormality detection device.
FIG. 4 is an explanatory diagram illustrating an operation state of the brake abnormality detection device in FIG. 3;
[Explanation of symbols]
22 Torque control means 23 Current command means 23a Output signal 30 of current command means 23 Load detector 30a Output signal 31 of load detector 30 Brake abnormality detector

Claims (4)

In an elevator that controls a motor for driving a car for driving an elevator car by a torque control unit that issues a torque command, and that drives the motor through a current command unit in a subsequent stage to maintain the stop of the elevator car by a brake device that restrains the motor,
Load detecting means for detecting the unbalanced load of the elevator and inputting the unbalanced load information to the torque control means; and providing an output signal of the load detecting means and an output signal of the current command means under a predetermined condition. A safety device for an elevator, comprising: a brake abnormality detecting means for comparing and detecting an abnormality of the brake device. The elevator safety device according to claim 1, wherein the predetermined condition is when the elevator car is started. The elevator safety device according to claim 1, wherein the predetermined condition is a time when the elevator car travels at a constant speed. The elevator safety device according to claim 1, wherein the predetermined condition is immediately before the stop of the elevator car.

Images