JPH0733228B2 - Elevator abnormality detection device - Google Patents

Description

Description: [Industrial application] The present invention relates to a device for detecting abnormal slippage of main ropes of a traction elevator.

[Prior Art] FIGS. 3 to 6 are views showing a conventional elevator abnormality detecting device disclosed in, for example, Japanese Patent Laid-Open No. 59-230981.
FIG. 3 is a block diagram, FIG. 4 is a circuit diagram of essential parts, FIG. 5 and FIG.
The figure is a diagram for explaining the operation.

In FIGS. 3 and 4, (1) is a speed command generator that outputs a speed command signal Pa, and (2) compares the speed command signal Pa with a speed signal Pb which will be output later, and outputs a deviation signal Pc. Adder,
(3) is a motor controller that outputs a voltage according to the deviation signal Pc, (4) is a main circuit electromagnetic contactor, (4a) and (4b) are normally open contacts, and (5) is a contact (4a) ( A hoisting motor connected to the electric motor control device (3) via 4b), and (6) for a speedometer that is directly connected to the electric motor (5) and generates a speed signal Pb corresponding to the rotation speed of the electric motor (5). Speed detector consisting of generator, (7) drive sheave of hoist driven by electric motor (5), (7A) releases sheave (7) when brake coil (7B) is energized However, when the brake coil (7B) is deenergized, an electromagnetic brake that gives a braking force to the sheave (7) by the force of a spring (not shown), (8) a deflector, and (9) a sheave (7). The main rope is wound around the deflector wheel (8), and the car (10) and the counterweight (11) are connected to both ends of the main rope. (12) and (13) are pulleys installed above and below the hoistway, (14) is a rope wound around the pulleys (12) and (13), and both ends of which are fixed to the car (10), (15) Is a speed detector that is coupled to the pulley (12) and generates a speed signal Pd corresponding to the rotation speed of the pulley (12), and (16) is a speed command signal Pa.
And a speed signal Pd are compared, and a comparator that generates a judgment signal Sa when the difference exceeds a set value, (17) is an abnormality detection relay that is activated when the judgment signal Sa is input, and (17a) is Normally-closed contacts, (18) are travel command relay contacts that are closed when a travel command is given, and (+) (-) are DC power supplies.

The conventional elevator abnormality detection device is configured as described above, and when a travel command is given, the travel command relay contact (18) is closed, and the main circuit electromagnetic contactor (4) is energized to contact (4a ) (4b) closes. Further, the brake coil (7B) is energized, and the electromagnetic brake (7A) releases the restraint of the sheave (7). On the other hand, the speed command signal Pa and the speed signal Pb are compared by the adder (2), the deviation signal Pc is input to the electric motor control device (3), and the voltage according to the value is applied to the electric motor (5). . Now the electric motor (5) will rotate,
The car (10) runs through the sheave (7). In this way, the electric motor control device (3) controls the rotational speed of the electric motor (5) so that the speed signal Pb matches the speed command signal Pa, and the speed of the car (10) is controlled with high accuracy.

On the other hand, the speed command signal Pa and the speed signal Pd are input to the comparator (16), but in a normal state, the difference between the two signals Pa and Pd is less than or equal to the set value, so the determination signal Sa is not output and the car ( The driving in 10) will be continued.

By the way, the rope groove of the sheave (7) gradually becomes mirror-like due to friction with the main rope (9). During this process, the main rope (9) may slip as shown in FIG. 5 (b). In this figure, after the elevator starts accelerating the car (10) in response to the speed command signal Pa,
At t ₁ , an abnormal slip occurs between the rope groove of the sheave (7) and the main rope (9), and then the traveling speed of the main rope (9) (that is, the traveling speed of the car (10)) Pr gradually increases. Speed command signal
It shows the case where it is separated from Pa. In the comparator (16), the speed command signal Pa and the speed signal Pd (corresponding to the main rope traveling speed Pr in FIG. 5 (b)) are compared, and the difference gradually increases, and if the set value is exceeded, it is judged. The signal Sa is output. Now, the abnormality detection relay (17) is energized, the contact (17a) is opened, the main circuit electromagnetic contactor (4) is deenergized, the contacts (4a) (4b) are opened, and the electric motor (5 Power supply to) is cut off. At the same time, since the brake coil (7B) is also deenergized, the electromagnetic brake (7A) operates and braking force is applied to the sheave (7), and the car (10 stops).

[Problems to be Solved by the Invention] In the conventional elevator abnormality detection device as described above,
Since the speed command signal Pa and the speed signal Pd are compared and the judgment signal Sa is output, the car (10) should be stopped when an abnormal slip shown in FIG. 5 occurs. However, in the case shown in FIG. 6 (b), the abnormality cannot be detected. Therefore, even if for some reason the above-mentioned signs of abnormal slippage of the main rope (9) begin to appear, it is difficult to take preventive maintenance measures at an early stage, and there is a risk of causing a serious accident. There is a problem that

That is, as shown in FIG. 6 (b), as described above, the main rope (9) slips at the time t ₁ , and the speed signal Pb and the main rope traveling speed are increased.
Although separation occurs with Pr, after that, after time t ₂ , the acceleration of the car (10) accelerates to follow the substantially normal acceleration as shown in FIG. 6 (e) to reach a predetermined speed. Shows when to reach. In this case, the difference between the speed command signal Pa and the speed signal Pd is a much larger value than the difference between these two signals Pa and Pd, which is determined by the responsiveness of the elevator drive system when abnormal slippage does not occur. In some cases, it is difficult to reliably detect the occurrence of abnormal slip even if a set value is set for the difference between signals related to speed.

The present invention has been made to solve the above problems, and accurately detects slippage of the main rope even if the difference between the speed command signal and the speed signal does not increase after the slippage of the main rope. It is an object of the present invention to provide an elevator abnormality detection device that is made possible.

[Means for Solving the Problems] An elevator abnormality detection device according to the present invention compares a rotation acceleration signal obtained by differentiating a rotation speed of an electric motor with a car acceleration signal, and when the difference exceeds a set value, the main rope is searched. The slip generation signal is generated.

Further, an elevator abnormality detecting means according to another invention of the present invention is adapted to compare a rotational acceleration signal obtained by differentiating a rotational speed of an electric motor with an electric current signal of the electric motor.

[Operation] In the present invention, the difference between the rotational acceleration signal and the car acceleration signal is detected, and in another invention of the present invention, the difference between the rotational acceleration signal and the electric motor current signal is detected. When the slippage occurs, the two signals to be compared with each other have opposite directions of change.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention, in which the same parts as in the conventional apparatus are designated by the same reference numerals. Incidentally, FIGS. 5 and 6 are also used in this embodiment.

In the figure, (20) differentiates the speed signal Pd to generate a rotation acceleration signal αb corresponding to the rotation acceleration of the electric motor (5), and (21) differentiates the speed signal Pd to correspond to the acceleration of the car. Differentiating circuit 2 for generating the cage acceleration signal αd,
(22) compares the rotational acceleration signal αb with the car acceleration signal αd, and if the difference exceeds the set value, the main rope slip generation signal (22
The comparator (abnormality detecting means) for emitting a) and (23) are main rope slip occurrence signal holding circuits for holding the main rope slip occurrence signal (22a) when input.

Next, the operation of this embodiment will be described with reference to FIG.

Now, assume that the acceleration command value α ^* is as shown in FIG. 6 (a), and during acceleration of the car (10), at time t ₁ in FIG. 6 (b), the sheave (10) and the main rope ( An abnormal slip occurs during 9), and then at time t ₂ , the cage determined by the frictional force that can be secured in the rope groove of the sheave (7) that is determined according to the main rope slip ratio at time t ₁ (10 ) And the car acceleration indicated by the speed command signal Pa at this time, and the car (10) starts to accelerate again at the normal acceleration.
At this time, since the sheave (7) spins ahead of the rotation of the main rope (9) between time (t ₁ -t ₂ ), the speed signal Pb that directly detects the rotation speed of the electric motor (5). Is accelerated with an abnormally large acceleration as compared with the normal case where no slip occurs. Therefore, in the rotational acceleration signal αb obtained by differentiating the speed signal Pb, as shown in FIG. 6 (d), the acceleration that is more prominent than usual during the slip occurrence period (t ₁ -t ₂ ). To be detected. Meanwhile, the basket (10)
The main rope (9) for driving the vehicle (9) does not sufficiently transmit the driving torque of the sheave (7) due to the slip of the main rope (9) during the period (t ₁ −t ₂ ), and the acceleration is abnormally reduced during this period. It will be. This abnormality is detected in the car acceleration signal αd obtained by differentiating the speed signal Pd as shown in FIG. 6 (e).
It will be output as a value smaller than the normal acceleration. Therefore, the comparator (22) outputs both of these signals αb, α.
It is possible to detect even a slight slip of the main rope (9) by detecting the change appearing in d that increases the difference between them and detecting whether the change exceeds the set value. This main rope slip generation signal (22a) is held by the holding circuit (23), and the main rope (9) is held at the time of regular inspection of the elevator.
It is possible to detect the occurrence of slippage and to take preventive maintenance measures.

Even in the case of FIG. 5B, the rotational acceleration signal α
The relationship between b and the car acceleration signal αd is shown in Fig. 5 (d).
As shown in FIG. 6 (e), it is the same as in the case of FIG. 6 (d) (e), and it is obvious that a minute slip of the main rope (9) can be detected.

FIG. 2 is a block diagram showing another embodiment of the present invention, in which a current transformer (24) for detecting the current flowing through the electric motor (5) is provided, and its output is sent to the comparator (22) as the electric motor current signal im. I am trying to enter it.

That is, the period (t ₁ −) in which the main rope (9) causes abnormal slippage.
At t ₂ ), since the sheave (7) idles in the direction preceding the main rope (9), the speed signal Pb is returned to the adder (2) with a larger value than when the slip is not occurring. The deviation signal Pc, which has become smaller than usual, commands a motor current sufficient to generate a motor torque smaller than usual. As a result, as shown in FIG. 6 (c) or FIG. 5 (c), the motor current signal im corresponding to the current flowing into the motor (5).
Is a value smaller than the normal value before the slip occurs, like the car acceleration signal αd in FIG. Therefore,
By monitoring the difference between the rotational acceleration signal αb and the electric motor current signal im, the slip of the main rope (9) can be detected with high accuracy.

In FIG. 1, the car acceleration signal αd is obtained by differentiating the output of the speed detector (15) coupled to the pulley (12) with the differentiating circuit (21). You may use the output of the detectors, such as an accelerometer directly installed in. Moreover, although the signal corresponding to the actual current flowing into the electric motor (5) is used as the electric motor current signal im in FIG. 2, a current command corresponding to the electric motor torque generated in the electric motor control device (3) is used. A value or torque command value may be used. Further, when the electric motor (5) is an AC electric motor, a command value of the torque current component or a current feedback signal can be used.

[Effects of the Invention] As described above, in the present invention, the difference between the rotational acceleration signal and the car acceleration signal is detected, and in another invention of the present invention, the difference between the rotational acceleration signal and the electric motor current signal is detected, and the difference is set. When the value exceeds the value, the main rope slip generation signal is generated, so that the two signals to be compared have opposite change directions, so that after the main rope slips,
Even when the difference between the speed command signal and the speed signal does not increase, the slip of the main rope can be detected with high accuracy.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an elevator abnormality detecting apparatus according to the present invention, FIG. 2 is a configuration diagram showing another embodiment of the present invention, and FIGS. 3 to 6 are conventional elevator abnormality. FIG. 3 is a diagram showing a detection device, FIG. 3 is a configuration diagram, FIG. 4 is a circuit diagram of a main part, and FIGS. 5 and 6 are operation explanatory diagrams. In the figure, (1) is a speed command generator, (5) is a hoisting electric motor, (6) is a speed detector, (7) is a drive sheave, (9) is a main rope, (10) is a basket, (15) is a speed detector, (20) is differential calculating means (differential circuit), (21) is car acceleration detecting means (differential circuit), (22) is an abnormality detecting device (comparator), (22)
a) is a main rope slip generation signal, (24) is current detection means (current transformer), Pa is a speed command signal, Pb and Pd are speed signals, αb is a rotational acceleration signal, αd is a car acceleration signal, and im is a motor. It is a current signal. The same reference numerals in the drawings denote the same parts.

Claims (2)

[Claims] 1. A car traveling through a main rope wound around a drive sheave driven by the electric motor by comparing the speed command signal with the rotational speed of the electric motor to control the rotational speed of the electric motor. In the one for controlling the speed, a differential calculation means for differentially calculating the rotation speed of the electric motor to output a rotation acceleration signal, a car acceleration detection means for outputting the acceleration signal of the car, the rotation acceleration signal and the car acceleration. An abnormality detecting apparatus for an elevator, comprising: an abnormality detecting unit that compares the signal and outputs a main rope slip occurrence signal when the difference exceeds a set value. 2. A car traveling via a main rope wound around a drive sheave driven by the electric motor by comparing the speed command signal with the rotational speed of the electric motor to control the rotational speed of the electric motor. In the one for controlling the speed, a differential operation means for differentiating the rotational speed of the electric motor to output a rotational acceleration signal, a current detecting means for detecting a current flowing through the electric motor and outputting an electric motor current signal, the rotation An abnormality detecting device for an elevator, comprising: an abnormality detecting unit that compares an acceleration signal with the electric current signal of the electric motor, and outputs a main rope slip occurrence signal when the difference exceeds a set value.