JP5070558B2 - Elevator safety equipment - Google Patents

Description

  The present invention relates to an elevator safety device that detects an abnormality in an elevator car speed and stops operation.

In the elevator, the long rope that moves the car up and down can be seen as an elastic body, and the vibration system is configured by the mass of the car and the rope. When continuous vibration is applied to this vibration system due to passenger mischief or earthquake, a resonance phenomenon occurs and the speed of the car may instantaneously exceed a predetermined value. In such a case, there is a possibility that the safety device breaks down and stops the car and traps the passenger in the car, even though no trouble has occurred.
Patent Document 1 describes that the torque of a motor that raises and lowers a car is detected, and that the change in the torque is generated in a shorter time than the change in torque of normal car acceleration and deceleration. Has been.
JP 2005-8271 A

  In the conventional technique, when the speed fluctuation changes in a vibrational manner, if the sensitivity of the vibration detector is lowered too much, the response of the safety device becomes slow, so the sensitivity cannot be lowered so much. For this reason, there is a possibility that an excessive speed due to resonance caused by a very large continuous vibration due to mischief is detected.

In addition, the conventional technology recognizes not only vibration due to resonance but also short-term fluctuations in speed as a slack operation. Could be restarted.
The object of the present invention is to move the car to the nearest floor and prevent the passenger from being trapped in the car if there is no dangerous failure even if the speed of the car is exceeded due to passenger mischief or earthquake. It is to provide a safety device.

In order to solve the above problems, an elevator safety apparatus according to the present invention includes a car speed measuring means for measuring the speed of an elevator car, a speed history recording means for recording the car speed, and a car position for measuring the position of the elevator car. Measuring means, and overspeed detecting means for detecting whether or not the car speed exceeds a predetermined value. Further, the present invention has a cage rope vibration model in which the cage mass, the elastic modulus of the rope, and the rope length are provided as parameters, and the rope length is changed according to the cage position obtained by the cage position measuring means.
Further, when the overspeed detection means detects an overspeed of the car, information from the speed history recorded in the speed history recording means and information from the car rope system vibration model are input to the filter means to obtain a speed waveform. The remaining components are removed, and other components are removed, and the total sum of displacements from the car speed reference is obtained by the waveform area calculation means, and it is determined whether the obtained value is equal to or greater than a predetermined threshold value. And a nearest floor return judging means for driving the car to the nearest floor when the speed history analyzing means judges that the speed history analyzing means is greater than or equal to a predetermined threshold value.
And, when driving the nearest floor to drive the car to the nearest floor by the nearest floor return judging means, the car is driven at a lower speed than normal, and the predetermined value that the speed excess detecting means judges to exceed the speed is higher than usual. Low value.

  In the elevator safety device according to the present invention, after detecting the overspeed of the car and stopping the car, the inherent vibration period is calculated from the car rope system vibration model, and the speed caused by continuous excitation due to mischief or earthquake It is possible to distinguish between overspeed and overspeed due to equipment abnormality, and move the car again to return to the nearest floor.

  First, an example of this embodiment will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of this embodiment. The car speed measuring means 1 is a means for measuring the traveling speed of the elevator car. As a specific configuration example, the rotational speed of the governor pulley that winds the rope is read and calculated by an encoder or the like. Further, since the car moves in the hoistway, it may be calculated by reading marks provided on the hoistway at regular intervals with a sensor provided on the car. Furthermore, the position of the car can be measured by a distance sensor installed at the lowermost or uppermost part of the hoistway, and the speed can be calculated from the amount of change.

  The car position measuring means 2 is means for measuring the position (floor position) of the elevator car. As a specific configuration example, calculation is performed from signals of an encoder provided in the governor pulley, a car, and a sensor provided in a hoistway. Further, it may be calculated from a car floor passing signal or a landing signal.

  The seismic motion measuring means 3 is a means for measuring the shaking of the earthquake acting on the elevator. A specific configuration example is an acceleration sensor installed at the upper or lower part of the hoistway. The speed history recording means 4 is a means for storing a time history of speeds from the current time to a predetermined time before. Similarly, the earthquake motion history recording means 5 is a means for storing the time history of the earthquake motion from the current time to a predetermined time before.

  The overspeed detecting means 6 monitors the speed signal of the car speed measuring means 1 and outputs a command for stopping the car to the elevator control device 10 when the car speed exceeds a predetermined value. The speed history analysis means 7 analyzes the speed history recorded in the speed history recording means and determines the presence or absence of a vibration component given by the car rope system vibration model 9. The nearest floor return determination means 8 determines that the car is the nearest floor when there is a vibration component peculiar to the car rope system in the speed history or when a large earthquake motion is recorded within a predetermined time immediately before the overspeed occurs. The nearest floor return command to move to the elevator control device 10 is output.

In the configuration as described above, first, a description will be given of a portion that operates when discriminating excess speed caused by mischief or continuous excitation due to earthquakes and excess speed due to device abnormality when the car speed exceeds a threshold value.
There are two cases of this operation. In the first case, a periodic vibration is generated by continuous excitation. In the second case, for example, when a large vibration is suddenly applied like a direct earthquake. It is.

(First case)
FIG. 2 shows a configuration example of the speed history recording unit 4. The car speed data from the car speed measuring means 1 is input to the selective writing means 43. The selective writing means 43 writes the speed data read by the car speed measuring means 1 in the storage area of the address 42 designated by the counter 44. In the memory device 41 that records the car speed read at regular time intervals, addresses 42 from 0 to n-1 are assigned to the respective storage areas. The counter 44 counts up from 0 to n-1 at regular time intervals, and returns to 0 again when it reaches n-1.

  When speed data is recorded with such a configuration, if speed data V (t) at the current time t is recorded at address 2 at a certain point in time, for example, speed data V ( t-1) is recorded. Similarly, speed data from the current time t to time t−n + 1 is recorded in the speed history recording means 4 in the form as shown in FIG. The detailed configuration of the earthquake motion history recording means 5 is the same as that shown in FIG.

  The speed data V (t) may be recorded at any address of the speed history recording means 4, and the first data need not necessarily be recorded at address 0 of the address 42. When the overspeed detection means 6 detects an overspeed of the car, the car speed recording stops, and the speed history analysis means 7 analyzes the speed history.

Next, when the car returns to the nearest floor and returns to normal operation, the speed history recording means 4 starts to record the car speed. At this time, the car speed data is recorded, for example, from the address next to the address where the latest car speed data is recorded, instead of starting from address 0 of address 42 in FIG.
Therefore, in FIG. 2, the speed data V (t) starts from address 2 at address 42. However, the present invention is not limited to this, and speed data may be recorded from address 0 of address 42 when the control of the car returns to normal operation.

  Next, details of the speed history analysis means 7 will be described. 3 (a) and 3 (b) show the car speed waveforms. An elevator car usually has a constant velocity movement after an acceleration movement. The vertical axes in FIGS. 3A and 3B are based on the velocity in the state of constant velocity motion. That is, “0” on the vertical axis does not mean that the speed is zero, but means that the fluctuation from the speed of a predetermined uniform motion is zero. The horizontal axis indicates time.

  When the passenger shakes the car with mischief or when the car is continuously vibrated by an earthquake, the speed waveform of the car becomes a resonant vibration waveform 11 as shown in FIG. On the other hand, when the elevator drive device fails, the rope and sheave slip, or the rope breaks, the car speed increases as shown in the non-vibration waveform 15 as shown in FIG. Therefore, when the car speed exceeds the overspeed determination threshold value 12, the state of speed change in a predetermined analysis section 14 is analyzed retroactively from that time (speed overtime 13 or 16). It can be determined whether it is caused by an earthquake or an earthquake, or caused by an apparatus abnormality.

FIG. 4 is a block diagram showing the speed history analysis means 7. As shown in FIG. 4, the speed history analysis means 7 includes a filter means 71, a waveform area calculation means 72, and a threshold value determination means 73 as shown in the figure.
The filter means 71 receives information from the speed history recording means 4 and information from the car rope system vibration model 9. This filter means 71 can remove other components while leaving only the vibrational component of the velocity waveform. Frequency characteristic of this filter is the characteristic of the band-pass filter as passed the center frequency f ₀ only near the frequency components as shown in FIG. 5, attenuates other frequency components. Here, the frequency f ₀ is a natural vibration frequency of a vibration system composed of an elevator rope and a car.

またロープの弾性ｋは、ロープの吊り点からかごの支持点までの長さ（ロープ長さ）Ｌによって変化し、例えば以下の式で与えられる。

ただし、ｋ_０は単位長さあたりのロープの弾性係数である。また、ロープ長さとは、かごの位置（階床位置）から求めることができる。 This natural vibration frequency can be obtained by a model as shown in FIG. This is a vibration system composed of an elevator rope and a car. In the figure, the mass element 91 corresponds to the mass m of the car, the spring element 92 corresponds to the elasticity k of the rope, and the damper element 93 corresponds to the frictional resistance c against the elastic deformation of the rope. To do. The damper element 93 and the spring element 92 are connected in parallel. The resonance frequency of such a vibration system is given by the following equation.

The elasticity k of the rope varies depending on the length (rope length) L from the suspension point of the rope to the support point of the car, and is given by the following equation, for example.

However, k ₀ is the elastic modulus of the rope per unit length. The rope length can be obtained from the position of the car (floor position).

As described above, the car rope vibration model 9 includes the car mass m, the elastic modulus k _{0 of} the rope, the rope length L, and the like as parameters, and the resonance frequency f ₀ can be calculated using the above formulas 1 and 2. Anything is acceptable. The rope length L may be rewritten according to the position of the car obtained by the car position measuring means.

Although the car mass varies depending on the number of passengers, since the car itself has a large mass, it does not affect as much as the rope length. Therefore, for example, in FIG. 5, f ₀ is the resonance frequency for the average number of passengers, and the upper cutoff frequency f _ch and the lower cutoff frequency f _cl are 1.5 times and 0.5 times f ₀ , respectively. The width may be set.
Or you may calculate and calculate the gross weight of a car and a passenger using signals, such as a loading weight sensor with which a car was equipped.

  As a result of the above filter processing, as shown in FIG. 7, the vibration waveform 71a after passing through the filter remains almost undamped, but the non-vibration waveform 71b due to the apparatus abnormality is greatly attenuated as compared with FIG. It becomes a waveform.

  Information is input to the waveform area calculation means 72 next to the filter means 71. The waveform area calculation means 72 is a means for obtaining the total displacement from the standard of the car speed. In FIG. 7, setting the car speed reference to 0 is the same as the description in FIG. 3 described above, and does not mean the speed 0 but means that the displacement from a predetermined speed is 0. The waveform area calculating means 72 calculates the total displacement from this reference. That is, the integrated value of the absolute value of the speed change is obtained (waveform area calculating means 72 in FIG. 4).

  Next, the threshold value judging means 73 judges whether or not the integrated value of the obtained absolute value of the speed is greater than or equal to a predetermined threshold value. When the integrated value of the absolute values of the speed is equal to or greater than a predetermined threshold value, it is determined that there is a vibration component, and when it is less than that, it is determined that there is no vibration component.

The above determination method may also be performed by spectral analysis of the velocity waveform. That is, FFT (Fast Fourier Transform) processing is performed on the velocity waveform, and the presence / absence of the vibration component is determined depending on whether or not the resonance frequency f ₀ calculated by the cage rope vibration model and the component in the vicinity thereof are equal to or higher than a predetermined value. judge.

  When the speed history analysis means 7 determines that there is a vibration component by the above processing, the nearest floor return determination means 8 performs the nearest floor return to move the car to the nearest floor after a predetermined time has elapsed since the car stopped. The command is output to the elevator control device 10. At this time, the moving speed of the car is set to a slower speed than usual for safety, and the overspeed threshold detected by the overspeed detecting means 6 is also set to a lower value than usual.

(Second case)
In the case of excessive speed due to an earthquake, a large vibration is suddenly applied as in a direct earthquake, so that the car speed 31 may exceed the speed without undergoing resonant vibration as shown in FIG. In consideration of such a situation, it is determined whether or not to return to the nearest floor in consideration of the presence of earthquake motion. Although this will be described in detail below, even if the car speed exceeds the threshold value, the return to the nearest floor is determined by detecting that the car speed returns below the threshold value before the brake operation time. .

  In FIG. 1, with respect to the overspeed time 13 when the overspeed detection means 6 detects the overspeed, the brake shoe time 17 (see FIG. 8) by which the brake is actually operated and the car starts to decelerate is started. A time difference occurs due to a delay time until the lining is inserted. The speed history analysis means 7 determines whether or not the car speed again falls below the threshold value within this time difference.

  Whether the nearest floor return determination means 8 records an amplitude such that the seismic motion 32 exceeds predetermined thresholds 34 and 35 in a search section 33 that is a predetermined interval from the time when the car speed exceeds the speed. Determine. This is performed using the earthquake motion history recorded in the earthquake motion history recording means 5. The nearest floor return determination means 8 determines that the speed of the car is below the threshold immediately after the speed is exceeded by the speed history analysis means 7 and records a large earthquake motion within a predetermined time before the speed is exceeded. In the event of a failure, a command to return to the nearest floor shall be output.

  Since the overspeed detection means 6 for detecting the excess of the car speed is determined by comparison with a threshold value, there is a possibility that the car will stop immediately due to mischief or vibration caused by an earthquake. Therefore, by reducing the sensitivity of the overspeed detection means 6 to fluctuations in speed, it is possible to reduce the unnecessary stopping of the car.

FIG. 9 shows a block diagram of the overspeed detection means 6. The filter means 61 reduces the component of the resonance frequency f ₀ calculated by the cage rope vibration model 9. Specifically, configuring a low-pass filter having a cutoff frequency f _c the frequency sufficiently lower than the frequency f ₀ as shown in FIG. 10 for example. The threshold signal judgment means 62 compares the speed signal with the vibration component inherent to the car rope system reduced to some extent by such a filter, and the threshold value judging means 62 judges whether the speed has been exceeded.

As the configuration of the filter unit 61, in addition to the low-pass filter characteristic as shown in FIG. 10, it may be a band eliminate filter for reducing only the frequency components in the vicinity thereof and the frequency f _c.

  As explained above, in both the first and second cases, when the car speed exceeds the threshold, after the car stops, the passenger is trapped in the car by returning to the nearest floor. Can be prevented. When the car returns to the nearest floor, vibrations caused by passengers and vibrations caused by earthquakes may occur. In this case, the same processing as described above is performed for the speed excess threshold value lower than normal set for the operation for returning to the nearest floor.

(Flowchart of elevator safety device operation)
Next, the flowchart of the whole operation | movement of the safety device of an elevator is demonstrated using FIG.
First, when an overspeed of the car is detected (step S1), the car is stopped (step S2). If the car does not stop and the speed further exceeds, the process proceeds to step S4, the emergency stop device is activated, and the car is stopped. If the car stops in step S3, the car speed and earthquake motion recording is interrupted (step S5).

  Next, the speed history is analyzed (step S6). In step S6, the speed of the car is analyzed (step S7), and if it is determined that there is vibration inherent in the car rope system, the speed excess threshold is lowered after a certain period of time and the car is moved to the nearest floor at a lower speed. (Step S11). If it is determined in step S7 that there is no vibration inherent in the car rope system, the process proceeds to the next step S8, where it is determined whether the car speed has decreased immediately after exceeding the threshold value. If the car speed does not decrease immediately, the car is put on standby without returning to the nearest floor (step S10).

  If the car speed decreases immediately after exceeding the threshold value in step S8, it is determined whether or not there has been a ground motion within a predetermined time before the car speed exceeds the threshold value (step S9). If there is an earthquake motion, the threshold for exceeding the speed is lowered after a predetermined time, and the car is returned to the nearest floor at a low speed (step S11). If not, the car is put on standby without returning to the nearest floor (step S10).

  In the above flow chart, the speed history recording means 4, the earthquake motion history recording means 5, the speed excess detection means 6, the speed history analysis means 7, the nearest floor return determination means 8, and the car rope system vibration model 9 are stored on a computer or a microprocessor. It can be configured as software.

It is a block diagram which shows an example of this Embodiment. It is a block diagram which shows a speed history recording means. A car speed vibration waveform and a non-vibration waveform. It is a block diagram which shows a speed history analysis means. It is a frequency characteristic of the filter means. This is a cage rope vibration model. It is the vibration waveform and non-vibration waveform of the car speed after passing through the filter means. The car speed waveform and the seismic motion waveform. It is a block diagram which shows a speed excess detection means. It is a frequency characteristic of a low-pass filter. It is a flowchart of an example of this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Car speed measuring means, 2 ... Car position measuring means, 3 ... Earthquake motion measuring means, 4 ... Speed history recording means, 5 ... Earthquake motion history recording means, 6 ... Overspeed Detection means, 7... Speed history analysis means, 8... Closest floor return determination means, 9... Car rope system vibration model, 10.

Claims (3)

Car speed measuring means for measuring the speed of the elevator car ;
Speed history recording means for recording the car speed;
Car position measuring means for measuring the position of the elevator car ;
Overspeed detecting means for detecting whether or not the car speed exceeds a predetermined value;
A car rope system vibration model in which the car mass, the elastic modulus of the rope, and the rope length are provided as parameters, and the rope length is changed according to the car position obtained by the car position measuring means;
When the overspeed detection means detects an overspeed of the car, information from the speed history recorded in the speed history recording means and information from the car rope system vibration model are input to the filter means to The remaining vibrational components of the waveform are removed, other components are removed, and the total sum of displacements from the car speed reference is obtained by the waveform area calculation means, and whether or not the obtained value is equal to or greater than a predetermined threshold value. A speed history analysis means for judging ;
When the speed history analysis means determines that it is equal to or greater than a predetermined threshold, the nearest floor return determination means for driving the car to the nearest floor,
The nearest floor return determining means drives the car to the nearest floor. During the nearest floor return operation, the car is driven at a lower speed than normal, and the predetermined value that the overspeed detection means determines to be overspeed is lower than normal. Elevator safety device with value. The overspeed detection means determines overspeed with respect to a signal that has passed through a filter that attenuates a vibration component determined by the car rope vibration model with respect to the speed signal obtained by the car speed measurement means. The elevator safety device according to claim 1 . The elevator safety device according to claim 1 or 2 , wherein the parameter of the car lobe vibration model is changed according to the position of the car measured by the car position measuring means.

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