Anomaly detection device for shaft of passenger conveyor, and elevator

Abstract

To provide a detection device that is able to immediately detect anomalies, such as torsion and breakage, in a shaft of a passenger conveyor.SOLUTION: An anomaly detection device 30 for a shaft 14 of a passenger conveyor, according to the present invention, is an anomaly detection device for a shaft that transmits power of a passenger conveyor, and includes: a first sensor 31 that detects rotation of the shaft and transmits a first signal; a second sensor 32 that is disposed at a position apart from the first sensor in an axial direction of the shaft, detects rotation of the shaft, and transmits a second signal; and a detection unit 33 that receives the first signal and the second signal and detects an anomaly in the shaft.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a device for detecting abnormalities in shafts used in passenger conveyors such as elevators and escalators, and to an elevator equipped with the same. [Background technology]

[0002] In passenger conveyors such as elevators and escalators, the rotational driving force of the motor is transmitted via a shaft. For example, in an elevator, the motor shaft is connected to the shaft of a reducer, and a brake device is installed between the motor and the reducer.

[0003] Due to deterioration over time or earthquakes, shafts can become twisted, broken, or otherwise damaged. If a shaft malfunction occurs while the motor is running, the motor continues to drive and the brake device will not activate. Since the car is generally lighter than the counterweight, if the shaft breaks, the car will move upward and will be detected by a limit switch located near the top of the elevator shaft, forcing it to stop.

[0004] Patent Document 1 discloses an elevator that detects slippage between the drive sheave and the main rope by attaching a resolver that detects the speed of the drive sheave and a resolver that detects the speed of the main rope to a speed governor and comparing the signals from both resolvers. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2015 / 083407 publication DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0006] Patent Document 1 is intended to detect slippage of the main rope, but not to detect twisting or breakage of the shaft.

[0007] An object of the present invention is to provide a detection device that can immediately detect abnormalities such as twisting or breakage of the shaft of a passenger conveyor. [Means for solving the problem]

[0008] The abnormality detection device for a shaft of a passenger conveyor of the present invention comprises: An abnormality detection device for a shaft that transmits power to a passenger conveyor, a first sensor that detects rotation of the shaft and sends a first signal; a second sensor disposed at a position spaced apart from the first sensor in the axial direction of the shaft, detecting rotation of the shaft and transmitting a second signal; a detection unit that receives the first signal and the second signal and detects an abnormality in the shaft; It is equipped with.

[0009] A motor, a brake device, and a reducer are arranged in a row from upstream to downstream in a drive unit that raises and lowers a car, and the shaft is a drive shaft whose base end projects from the motor to the upstream side and whose tip end passes through the brake device and is connected to the reducer, One of the first sensor or the second sensor can be positioned near the base end of the shaft extending upstream from the motor, and the other can be positioned between the brake device and the reducer to detect rotation of the shaft.

[0010] The detection unit can determine that there is no abnormality in the shaft when the first signal and the second signal are received in a predetermined pattern, and can determine that there is an abnormality in the shaft when the first signal and the second signal deviate from the pattern.

[0011] The first signal and the second signal are both on / off signals, and when there is no abnormality in the shaft, the on signals of the first signal and the second signal do not overlap, and when the on signals of the first signal and the second signal overlap, the detection unit can determine that there is an abnormality in the shaft.

[0012] The first sensor and the second sensor are proximity sensors.

[0013] The passenger conveyor of the present invention is an elevator, Any one of the passenger conveyor shaft abnormality detection devices described above; a drive unit that raises and lowers the car; a safety circuit that cuts off power supply to the drive unit; and The drive unit includes a motor, a brake device, and a reducer arranged side by side, and the shaft is a drive shaft having a base end that projects upstream from the motor and a tip end that penetrates the brake device and is connected to the reducer, one of the first sensor and the second sensor is disposed near a base end of the shaft protruding from the motor to the upstream side, and the other is disposed between the brake device and the reducer so as to detect rotation of the shaft; When the detection unit detects an abnormality in the shaft, it shuts off the safety circuit. [Effects of the Invention]

[0014] According to the passenger conveyor shaft abnormality detection device of the present invention, it is possible to detect an abnormality in the shaft from the first signal and the second signal. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is an explanatory diagram of an elevator shaft equipped with a shaft abnormality detection device of the present invention. [Figure 2]FIG. 2 is a diagram illustrating the positional relationship between the first detection unit and the first sensor on the tip side of the shaft, where (a) shows an embodiment in which the tip of the shaft is rectangular, and (b) shows an embodiment in which the tip is semi-cylindrical. [Figure 3] FIG. 3 is a diagram showing the positional relationship between the second detected part and the second sensor, which are arranged between the brake device and the reducer. [Figure 4] Figure 4 shows (a) the on / off signal pattern of the first signal when the first detected part is a rectangular shaft, (b) the on / off signal pattern of the second signal when the second detected part is a block piece, (c) a normal pattern in which the on signals of the first signal and the second signal do not overlap, and (d) an abnormal detection pattern in which the on signals of the first signal and the second signal overlap. [Figure 5] Figure 5 shows (a) the on / off signal pattern of the first signal when the first detected part is a semi-cylindrical shaft, (b) the on / off signal pattern of the second signal when the second detected part is a block piece, (c) a normal pattern in which the on signals of the first signal and the second signal do not overlap, and (d) an abnormal detection pattern in which the on signals of the first signal and the second signal overlap. [Figure 6] FIG. 6 is a block diagram of the detection unit. [Figure 7] Figure 7 is a photograph of the exterior of the detection unit. [Figure 8] FIG. 8 is a graph showing the normal states of the first signal, the second signal, the abnormality detection relay, the safety circuit, the brake device, and the car speed. [Figure 9] FIG. 9 is an enlarged view of the period from 7.44 seconds to 7.49 seconds in FIG. [Figure 10] Figure 10 shows photographs of the first sensor attached to the base end of the shaft, where (a) is an example of cantilever support and (b) is an example of double-sided support. [Figure 11] This is a photo of the second sensor installed between the brake device and the reducer. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Note that although an elevator will be used as an example of a passenger conveyor, the passenger conveyor may also be an escalator.

[0017] Figure 1 is a schematic diagram of an elevator drive unit 10 according to one embodiment of the present invention. The elevator is constructed by connecting a car in which passengers board and a counterweight that balances the car with a main rope in an elevator shaft and suspending them with a sheave. The sheave is connected to the drive unit 10 and is rotatable.

[0018] As shown in Fig. 1, the drive unit 10 includes a motor 11 that serves as a hoist, a braking device 12, and a reduction gear 13. The motor 11, braking device 12, and reduction gear 13 are arranged such that the motor 11 is on the upstream side, the braking device 12 is on the midstream side, and the reduction gear 13 is on the downstream side.

[0019] The motor 11, braking device 12, and reducer 13 are connected by a shaft 14, which serves as a drive shaft. The shaft 14 has a base end 14a that projects from the upstream side of the motor 11, and a tip end that extends to the reducer 13. The shaft 14 may be a single, seamless piece, or may be made up of multiple shafts connected by bolts or the like. Furthermore, as shown in FIG. 11 , when the brake drum 12a of the braking device 12 and the shaft 14 are connected so as to be rotatable together, the present invention also includes the brake drum 12a, which rotates together, in the shaft 14.

[0020] The motor 11 is an electric motor that rotates the shaft 14. The motor 11 may be, for example, an inverter-controlled motor, but is not limited to this.

[0021] The brake device 12 is a braking device that brakes the rotation of the shaft 14. The brake device 12 can be, for example, a drum-type electromagnetic brake device (see FIG. 11) or a disk-type electromagnetic brake device, but is not limited to these.

[0022] The reducer 13 drives the sheave by reducing the rotation speed of the shaft 14. The reducer 13 may be, for example, a helical gear type or a worm gear type, but is not limited to these.

[0023] The drive unit 10 is controlled by a control panel 20 in response to hall calls and car calls. The control panel 20 is provided with a safety circuit 21, a common elevator component. The safety circuit 21 is a safety device that cuts off the power supply to the elevator and safely stops the car in the event of a malfunction or defect in the elevator drive unit 10, control equipment, or car travel, door opening, or door closing, or upon detecting an earthquake, flooding, or the like.

[0024] The elevator of the present invention is provided with an abnormality detection device 30 in the shaft 14. The abnormality detection device 30 includes a first sensor 31, a second sensor 32, and a detection unit 33 that receives output signals from these sensors 31 and 32 and detects abnormalities.

[0025] The first sensor 31 and the second sensor 32 are sensors that detect the rotation of the shaft 14 and send a first signal and a second signal, respectively. For example, the sensors 31 and 32 can be proximity sensors. Examples of proximity sensors include, but are not limited to, capacitance, induction, and magnetic proximity sensors. Furthermore, the sensors 31 and 32 are not limited to proximity sensors and may also be photocouplers or the like.

[0026] The first sensor 31 and the second sensor 32 are disposed at positions spaced apart in the axial direction of the shaft 14. The longer the distance between the sensors 31 and 32, the wider the abnormality detection area of ​​the shaft 14 can be, which is desirable.

[0027] In the embodiment of Figure 1, the first sensor 31 is positioned near the base end 14a of the shaft 14, i.e., the part protruding from the upstream side of the motor 11, so as to be detectable, and the second sensor 32 is positioned between the brake device 12 and the reducer 13 so as to be detectable.

[0028] When the sensors 31 and 32 are proximity sensors, the shaft 14 is provided with detection targets 51 and 52 that can be detected by the sensors 31 and 32.

[0029] 2(a), if the base end 14a of the shaft 14 is rectangular, the first detectable portion 51 detected by the first sensor 31 is a corner of the rectangle, and if the base end 14a of the shaft 14 is semi-cylindrical or semi-cylindrical, as shown in FIG. 2(b), the arc portion becomes the first detectable portion 51. The first sensor 31 can be disposed close to the transition path of the first detectable portion 51, as shown in the figure.

[0030] When the cross section of the shaft 14 is circular, the second detectable portion 52 detected by the second sensor 32 may have a convex shape on part of the circumferential surface of the shaft 14, as shown in Figure 3. In the case of an existing shaft 14, the second detectable portion 52 may have a block piece 52a attached to the circumferential surface of the shaft 14. The block piece 52a can be attached to the shaft 14 with a metal cable tie 52b. The second sensor 32 can be positioned close to the transition path of the second detectable portion 52, as shown in the figure.

[0031] The first sensor 31 detects the first detectable portion 51 and sends a first signal. The second sensor 32 detects the second detectable portion 52 and sends a second signal. The first signal and the second signal can be on / off signals, and for example, the sensors 31 and 32 can be configured to send an on signal when they detect the detectable portions 51 and 52 and to send an off signal when they are not detecting the detectable portions 51 and 52. The first signal and the second signal may be a high / low signal, a 0 / 1 signal, or the like.

[0032] The first signal and the second signal sent from the first sensor 31 and the second sensor 32 are received by the detection unit 33 as shown in Fig. 1. The detection unit 33 determines that the shaft 14 is normal if the first signal and the second signal are received in a predetermined pattern, and determines that the shaft 14 is abnormal if the first signal and the second signal are received deviating from the predetermined pattern. The predetermined pattern will be explained in the examples.

[0033] The detection unit 33 is electrically connected to the safety circuit 21, and when the detection unit 33 determines that an abnormality has occurred in the shaft 14, it notifies the safety circuit 21 of the occurrence of the abnormality, and the safety circuit 21 then stops the operation of the car. Because the first and second signals are sent during one rotation of the shaft 14, it is possible to immediately detect the occurrence of an abnormality such as twisting or breakage in the shaft 14 between the first sensor 31 and the second sensor 32, for example, between the motor 11 and the brake device 12, and stop the operation of the car.

[0034] The abnormality detection device 30 can be easily retrofitted to existing elevators as well as incorporated into new elevators. Another advantage of the abnormality detection device 30 is that it can be manufactured relatively inexpensively. [Example]

[0035] <First Example> The following is an example of a predetermined pattern of signal detection by the detection unit 33. It is assumed that the first sensor 31 and the second sensor 32 send an ON signal when they detect the detected parts 51 and 52, and send an OFF signal when they do not detect the detected parts 51 and 52.

[0036] FIG. 4(a) shows the on / off signal pattern of the first signal when the first detectable portion 51 is a corner of the shaft 14 whose base end 14a is rectangular, as shown in FIG. 2(a). FIG. 4(b) shows the on / off signal pattern of the second signal when the second detectable portion 52 is the block piece 52a shown in FIG. 3. During one rotation of the shaft 14, the first signal includes four on signals and the second signal includes one on signal. During one cycle of the shaft 14, the on:off ratio of the first signal is 84:16, and the on:off ratio of the second signal is 3:97. When the rotation speed of the shaft 14 is 16.6 rps, one cycle of the shaft 14 is approximately 0.06 seconds.

[0037] As shown in FIG. 4(c), when the first and second signals have a pattern where the ON signals do not overlap, it is desirable to determine that there is no abnormality in the shaft 14, and when the ON signal of the first signal and the ON signal of the second signal overlap as shown in FIG. 4(d) due to torsion or breakage of the shaft 14, it is determined that there is an abnormality in the shaft 14. To achieve this configuration, it is necessary to shift the angle of the second detectable portion 52 relative to the first detectable portion 51. Specifically, as shown in FIG. 2(a), when the shaft 14 is configured so that the first detectable portion 51 is at 0°, 90°, 180°, or 270°, the second detectable portion 52 may be positioned at, for example, 45°.

[0038] The reason why a pattern where the ON signals do not overlap is considered normal and a pattern where the ON signals overlap is considered abnormal is to prevent the elevator operation from being hindered if the abnormality detection device 30 malfunctions. In other words, if the installation position of the sensors 31 and 32 is shifted or if the sensors 31 and 32 are damaged or malfunctioning, the corresponding sensor will send out an OFF signal, preventing the ON signals from overlapping and leading to the shaft 14 being determined to be abnormal.

[0039] Of course, a pattern may be adopted in which a normal state is when the first signal is on and the second signal is on, and an abnormal state is determined when both the first and second signals are on. Alternatively, a pattern may be adopted in which a normal state is when the first signal is off and the second signal is on, or when the first signal is on and the second signal is off, and an abnormal state is determined when both the first and second signals are on or both are off.

[0040] If shaft 14 breaks while the car is traveling, the abnormality can be detected immediately as described above. However, if the weight of the car, including passengers, is unbalanced with the weight of the counterweight, the weight of the counterweight may cause the car to travel at the rated speed. For example, this may occur when the car is traveling upward with a light load. In this case, the abnormality in shaft 14 cannot be detected while the car is traveling at the rated speed, but when the motor 11 decelerates as the car approaches the landing floor where it should stop, the signals from sensors 31 and 32 deviate from the specified pattern, and the abnormality in shaft 14 can be detected.

[0041] <Second Example> Fig. 5(a) shows the ON / OFF signal pattern of the first signal when the first detected part 51 is the arc part of the semi-cylindrical shaft 14. The second detected part 52 in Fig. 5(b) is the same as in the first embodiment. In this case, a normal pattern in which the ON signals do not overlap is shown in Fig. 5(c), and an abnormal pattern in which the ON signals overlap is shown in Fig. 5(d).

[0042] <Third Example> FIG. 6 shows a specific circuit configuration of the abnormality detection device 30. The abnormality detection device 30 is connected to a power supply circuit 40 and a first sensor 31 and a second sensor 32 that operate by receiving power from the power supply circuit 40. A first LED 41 and a second LED 42 are connected in series to the first sensor 31 and the second sensor 32, respectively. A first transistor 44 that operates in conjunction with the first LED 41 and a second transistor 45 that operates in conjunction with the second LED 42 are connected in series to these, and an abnormality detection LED 43 that lights up when an abnormality is detected is connected to these. The abnormality detection device 30 also includes an abnormality detection transistor 46 that operates in conjunction with the abnormality detection LED 43 and an abnormality detection relay 47 that operates and self-holds when an abnormality is detected. The contacts of the abnormality detection relay 47 are added to the safety circuit 21.

[0043] The first LED 41 and the first transistor 44, the second LED 42 and the second transistor 45, and the abnormality detection LED 43 and the abnormality detection transistor 46 can each be configured from a card relay.

[0044] Normally, either the first sensor 31 or the second sensor 32 is off, so the first transistor 44 and the second transistor 45 are not simultaneously in a conducting state, and therefore the abnormality detection LED 43 remains unlit.

[0045] In the abnormality detection device 30 configured as described above, when an abnormality occurs in the shaft 14 and the first sensor 31 and second sensor 32 turn on simultaneously, the first transistor 44 and second transistor 45 turn on in conjunction with the first LED 41 and second LED 42, and the abnormality detection LED 43 lights up. This turns on the abnormality detection transistor 46, which turns on the abnormality detection relay 47, which then cuts off the safety circuit 21, cutting off the power supply to the drive unit 10 and stopping the car.

[0046] Figure 7 is a photograph of the exterior of the detection unit 33 of the abnormality detection device 30. Although not shown in Figure 6, the power supply LED 48 of the power supply circuit 40, the first LED 41, the second LED 42, and the abnormality detection LED 43 described above are lined up. The detection unit 33 is placed in a position that can be seen by workers during maintenance, and under normal conditions, the power supply LED 48 is lit and the first LED 41 and the second LED 42 repeatedly flash. The abnormality detection LED 43 remains off. If an abnormality occurs in the shaft 14, the abnormality detection LED 43 lights up, allowing the worker to visually identify that the abnormality has occurred in the shaft 14. When an abnormality occurs, it is desirable to restore the elevator by resetting its power supply.

[0047] Fig. 8 is a graph showing the first signal, the second signal, the on / off state of the abnormality detection relay 47, the on / off state of the safety circuit 21, the on / off state of the brake device 12, and the speed of the car, and shows the results of a simulation in which an abnormality is intentionally caused in the shaft 14 from normal operation. Fig. 9 is an enlarged view of the period from 7.44 seconds to 7.49 seconds in Fig. 8.

[0048] Referring to Figure 8, acceleration began at approximately 2 seconds, and the car accelerated and transitioned to rated speed. After 7.44 seconds, an abnormality occurred in shaft 14. As a result, as shown in Figure 9, both the first and second signals turned on (A in Figure 9). Thereafter, abnormality detection relay 47 was turned on with a delay of 1.3 ms (B in Figure 9). Safety circuit 21 was turned off with a delay of 12.2 ms (C in Figure 9). There was a delay of 25.2 ms (D in Figure 9) before brake device 12 was turned off and activated by safety circuit 21. There was also a delay of 112 ms before the car started to stop, and a delay of 1092 ms before the car stopped. According to this example, it took 2071 ms from the detection of an abnormality in shaft 14 to the car stopping.

[0049] It is desirable that after both the first and second signals are turned on, the abnormality detection relay 47 is turned on within 5 ms, the safety circuit 21 is turned off within 15 ms, the brake device 12 is turned off and activated by the safety circuit 21 within 100 ms, and the car is stopped within 1500 ms.

[0050] In this way, the shaft 14 abnormality detection device 30 of the present invention can detect abnormalities in the shaft 14 in a short time and stop the car, thereby improving the safety of the elevator.

[0051] <Fourth Example> FIG. 10 is a photograph showing the first sensor 31 attached to the base end 14a of the shaft 14. FIG. 10(a) shows an example of cantilever support, and FIG. 10(b) shows an example of double-sided support. In FIG. 10(a), an L-shaped mounting member 60 is attached to the motor casing 11a, and the first sensor 31 is attached to the mounting member 60 opposite the base end 14a of the shaft 14 and close to the transition path of the corner that becomes the first detected portion 51. In FIG. 10(b), a U-shaped mounting member 60 is attached to the motor casing 11a, and the first sensor 31 is attached. In either case, the first sensor 31 was firmly attached, and no displacement or shaking of the first sensor 31 occurred even when the motor 11 or the brake device 12 was operated.

[0052] FIG. 11 is a photograph showing the second sensor 32 mounted between the brake device 12 and the reducer 13. A block piece 52a, which is the second detection unit, is attached to the brake drum 12a with a cable tie 52b (not visible in the photograph). The mounting member 61 for the second sensor 32 is configured by bolting together vertical legs 62b, 63b of L-shaped metal fittings 62, 63 so that the lower leg 62a and the upper leg 63a are facing in opposite directions, and the lower leg 62a is attached to the frame 10a of the drive unit. The mounting member 61 mounts the second sensor 32 with the upper leg 63a of the L-shaped metal fitting 63 close to the transition path of the block piece. According to this embodiment, the height of the second sensor 32 can be easily adjusted by changing the bolt-fastening positions of the vertical legs 62b, 63b of the L-shaped metal fittings 62, 63.

[0053] The above description is for the purpose of explaining the present invention, and should not be construed as limiting the invention described in the claims or narrowing its scope. Furthermore, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications are possible within the technical scope described in the claims.

[0054] For example, in the above embodiment, the shaft abnormality detection device 30 is described using an elevator as an example, but the present invention is not limited to elevators and can also be applied to passenger conveyors such as escalators. Furthermore, the shaft abnormality detection device 30 of the present invention can be used to detect abnormalities in the shafts of various mechanisms that transmit power by shafts, such as industrial machinery, machine tools, household electrical appliances, vehicles, trains, aircraft, ships, etc. [Explanation of symbols]

[0055] 10 Drive unit 11 Motor 12 Brake equipment 13 Reducer 14 shaft 21 Safety circuit 30 Anomaly detection device 31 First Sensor 32 Second Sensor 33 Detection unit 51 First detected part 52 Second detected part

Claims

1. An abnormality detection device for a shaft that transmits power to a passenger conveyor, a first sensor that detects rotation of the shaft and sends a first signal; a second sensor disposed at a position spaced apart from the first sensor in the axial direction of the shaft, detecting rotation of the shaft and transmitting a second signal; a detection unit that receives the first signal and the second signal and detects an abnormality in the shaft; An abnormality detection device for a passenger conveyor shaft, comprising:

2. A motor, a brake device, and a reducer are arranged in a row from upstream to downstream in a drive unit that raises and lowers a car, and the shaft is a drive shaft whose base end projects from the motor to the upstream side and whose tip end passes through the brake device and is connected to the reducer, One of the first sensor and the second sensor is disposed near a base end of the shaft protruding upstream from the motor, and the other is disposed between the brake device and the reducer to detect rotation of the shaft.

2. The passenger conveyor shaft abnormality detection device according to claim 1.

3. the detection unit determines that the shaft is normal when the first signal and the second signal are received in a predetermined pattern, and determines that the shaft is abnormal when the first signal and the second signal deviate from the pattern; 3. The passenger conveyor shaft abnormality detection device according to claim 2.

4. The first signal and the second signal are both on / off signals, and when there is no abnormality in the shaft, the on signals of the first signal and the second signal do not overlap, and when the on signals of the first signal and the second signal overlap, the detection unit determines that there is an abnormality in the shaft.

4. The passenger conveyor shaft abnormality detection device according to claim 3.

5. the first sensor and the second sensor are proximity sensors; 5. The abnormality detection device for a shaft of a passenger conveyor according to claim 4.

6. the passenger conveyor is an elevator; The abnormality detection device for a shaft of a passenger conveyor according to any one of claims 1 to 5; a drive unit that raises and lowers the car; a safety circuit that cuts off power supply to the drive unit; and The drive unit includes a motor, a brake device, and a reducer arranged side by side, and the shaft is a drive shaft having a base end that projects upstream from the motor and a tip end that penetrates the brake device and is connected to the reducer, one of the first sensor and the second sensor is disposed near a base end of the shaft protruding from the motor to the upstream side, and the other is disposed between the brake device and the reducer so as to detect rotation of the shaft; When the detection unit detects an abnormality in the shaft, the detection unit cuts off the safety circuit. Passenger conveyor.

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