Elevator device

Abstract

An elevator device (10) according to the present invention is characterized by comprising a car (11) that moves along a hoistway, an overspeed detection unit that detects that the speed of the car (11) has reached a reference speed, a braking unit that applies a braking force to the movement of the car (11), a malfunction detection unit that detects a malfunction of the overspeed detection unit, a speed measurement unit that measures the speed of the car (11) if the overspeed detection unit detects that the speed of the car (11) has reached the reference speed, and a rescue operation unit that performs a rescue operation if the malfunction detection unit detects a malfunction of the overspeed detection unit, wherein if the speed measurement unit detects that the speed of the car (11) has reached an abnormal speed during the rescue operation, the braking unit applies a braking force to the movement of the car (11).

Description

elevator equipment

[0001] The present invention relates to an elevator device.

[0002] Patent Document 1 discloses an elevator system equipped with a safety device that stops the movement of a car when the speed of the car reaches a reference speed. In the elevator system of Patent Document 1, if the safety device is activated and a passenger is trapped inside the car, a remote operator determines for himself whether the safety device operated normally. If the safety device malfunctions, the operator shorts the circuit of the safety device and performs rescue operation.

[0003] Japanese Patent Application Laid-Open No. 2001-220075

[0004] As described above, in the elevator system disclosed in Patent Document 1, if the car stops due to a malfunction of the safety device, the circuit of the safety device is short-circuited and disabled before a rescue operation is performed. Therefore, if the car exceeds the speed limit during rescue operation, the safety device cannot be activated.

[0005] The elevator device of the present invention comprises a car that moves in a hoistway, an operation control unit that controls the movement of the car, an overspeed detection unit that detects when the speed of the car has reached a reference speed, a braking unit that applies a braking force to the movement of the car when the overspeed detection unit detects that the speed of the car has reached the reference speed, a malfunction detection unit that detects a malfunction of the overspeed detection unit, a speed measurement unit that measures the speed of the car when the overspeed detection unit detects that the speed of the car has reached the reference speed, and a rescue operation unit that performs rescue operation while measuring the speed of the car with the speed measurement unit when the malfunction detection unit detects a malfunction of the overspeed detection unit, and is characterized in that during rescue operation, when the speed measurement unit detects that the speed of the car has reached an abnormal speed, the braking force is applied to the movement of the car by the braking unit.

[0006] According to this configuration, when the speed of the car reaches the reference speed during rescue operation, the braking unit can apply a braking force to the movement of the car, thereby enabling rescue operation to be performed while ensuring the safety of passengers.

[0007] Furthermore, the malfunction detection unit may determine that the overspeed detection unit has malfunctioned if the speed of the car measured by the speed measurement unit at the time when the overspeed detection unit detects that the speed of the car has reached the reference speed is smaller than the reference speed. Furthermore, the speed measurement unit may measure the speed of the car from the time when the overspeed detection unit detects that the speed of the car has reached the reference speed. With this configuration, the time required to measure the speed of the car is shortened, and the memory capacity provided in the elevator device can be reduced.

[0008] The speed measurement unit may also measure the speed of the car based on information from an acceleration sensor. The acceleration sensor may measure acceleration in three axial directions, and the speed measurement unit may measure the speed of the car using the resultant acceleration measured in the three axial directions. This configuration facilitates accurate measurement of the car's speed even when the measurement direction of the acceleration sensor does not strictly match the direction of movement of the car. As a result, the acceleration sensor's measurement direction does not need to strictly match the direction of movement of the car, making it easier to install the acceleration sensor.

[0009] The acceleration sensor measures acceleration in three axes, and the elevator system further includes an abnormality detection unit that detects an abnormality in the acceleration sensor based on the acceleration in a direction perpendicular to the car's movement among the three measured accelerations in the three axes. If the abnormality detection unit detects an abnormality in the acceleration sensor during rescue operation, the brake unit may apply a braking force to the car's movement. Cars typically do not move in a direction perpendicular to their movement direction (e.g., the vertical direction). Therefore, if the acceleration sensor is normal, the acceleration in the direction perpendicular to the car's movement will be close to zero. In other words, if the measured acceleration in the direction perpendicular to the vertical direction is greater than a predetermined value, it can be said that an abnormality in the acceleration sensor may exist. Therefore, by applying a braking force to the car's movement when an abnormality in the acceleration sensor is detected during rescue operation, rescue operation can be performed while further ensuring the safety of passengers.

[0010] The speed measurement unit may measure the speed of the elevator car based on information from a plurality of sensors, such as a plurality of acceleration sensors, a plurality of speed sensors, or a plurality of position sensors. This configuration allows the speed of the elevator car to be measured more accurately, and rescue operations can be performed while further ensuring the safety of passengers.

[0011] Furthermore, during rescue operation, if the variation in the measurement values ​​of the multiple sensors is equal to or greater than a predetermined value, a braking force may be applied to the movement of the elevator car by the braking unit. If the variation in the measurement values ​​of the multiple acceleration sensors is equal to or greater than a predetermined value, there is a possibility that an abnormality has occurred in the sensor. Therefore, by stopping rescue operation if the variation in the measurement values ​​of the multiple sensors is equal to or greater than a predetermined value during rescue operation, rescue operation can be performed while further ensuring the safety of passengers.

[0012] The elevator apparatus according to the present invention may further include a communication device capable of communicating with a monitoring center that performs remote monitoring, and the rescue operation unit may perform rescue operation based on instructions from the monitoring center.

[0013] According to the elevator apparatus of the present invention, rescue operation can be performed while ensuring the safety of passengers.

[0014] FIG. 1 is a schematic diagram showing an elevator system including an elevator apparatus that is an example of an embodiment; FIG. 2 is a block diagram showing the configuration of an elevator system including an elevator apparatus that is an example of an embodiment; FIG. 3 is a flowchart showing the processing procedure in rescue operation that is an example of an embodiment; FIG. 4 is a diagram schematically showing an example of the speed of a car of an elevator apparatus that is another example of an embodiment; FIG. 5 is a flowchart showing the processing procedure in rescue operation that is another example of an embodiment; FIG. 6 is a block diagram showing the configuration of an elevator system including an elevator apparatus that is another example of an embodiment; FIG. 7 is a flowchart showing the processing procedure in rescue operation that is another example of an embodiment.

[0015] Hereinafter, an embodiment of an elevator device according to the present invention will be described in detail with reference to the drawings. The embodiment described below is merely an example, and the present invention is not limited to the following embodiment. Furthermore, the present invention also includes configurations that are formed by selectively combining multiple embodiments and modified examples described below.

[0016] [First Embodiment] An elevator system 1 including an elevator apparatus 10 according to a first embodiment will be described in detail with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing the elevator system 1 according to this embodiment, and Figure 2 is a block diagram showing the configuration of the elevator system 1.

[0017] 1 and 2, an elevator system 1 includes an elevator apparatus 10. The elevator apparatus 10 is connected to a remotely located monitoring center 2 via a network. The monitoring center 2 has, for example, an operator who monitors the elevator apparatus 10. The operator transmits commands related to the operation of the elevator apparatus 10 to the elevator apparatus 10 as necessary.

[0018] The elevator device 10 has a car 11, a hoisting machine 12, and a governor 13 as an overspeed detection unit.

[0019] The car 11 is installed in a hoistway 14, which is provided as a space extending vertically within a building. The car 11 is provided with a car door 15. When the car 11 arrives at a landing, a hall door 16 provided at the landing opens in conjunction with the car door 15, allowing passengers to get on and off. In this embodiment, a machine room 17 is provided above the ceiling of the hoistway 14.

[0020] One end of a main rope 18 is connected to the car 11. A counterweight 19 is connected to the other end of the main rope 18. An intermediate portion of the main rope 18 is wound around a drive sheave of the hoisting machine 12, and the main rope 18 moves with the rotation of the drive sheave of the hoisting machine 12. As a result, the car 11 and the counterweight 19 rise and fall in opposite directions.

[0021] The hoisting machine 12 is disposed in the machine room 17 and drives the car 11. The hoisting machine 12 is provided with a brake device 20. The brake device 20 corresponds to the braking section of the present invention. The brake device 20 generates a force to prevent the rotation of the drive sheave of the hoisting machine 12, and applies a braking force to the movement of the car 11. The brake device 20 prevents the rotation of the drive sheave, for example, by a frictional force generated when a brake shoe is pressed against a braking surface that rotates in conjunction with the drive sheave by a spring force.

[0022] Although the details will be described later, the brake device 20 is activated when the speed governor 13 detects that the speed of the car 11 has reached a reference speed. Note that the brake device 20 may be provided as one of the functions of the hoisting machine 12.

[0023] The governor 13 includes, for example, a governor rope 21 which is a single looped rope, a governor wheel 22 arranged in the machine room 17, a tension wheel 23, a pendulum (not shown) provided on the governor wheel 22, and an electric switch 24. The governor rope 21 is a looped rope arranged vertically within the hoistway 14. The folded portion of the governor rope 21 at its upper end is wound around the governor wheel 22, and the folded portion of its lower end is wound around the tension wheel 23. The governor rope 21 is connected and fixed to the car 11 so as to move in conjunction with the ascending and descending movement of the car 11.

[0024] When the car 11 moves up and down, the governor rope 21 moves in conjunction with it, causing the governor wheel 22 to rotate. As a result, a pendulum attached to the governor wheel 22 moves away from the center of the governor wheel 22. At this time, when the speed of the car 11 reaches a reference speed, the pendulum hits an electric switch 24. This allows the governor 13 to detect that the speed of the car 11 has reached the reference speed. When the governor 13 detects that the speed of the car 11 has reached the reference speed, it transmits a signal to a control device 30, which will be described later.

[0025] The elevator device 10 further includes an acceleration sensor 25. In this embodiment, the acceleration sensor 25 is disposed on the top surface of the car 11. The acceleration sensor 25 detects the acceleration of the car 11 in one or more axial directions including at least the vertical direction. The acceleration sensor 25 transmits the measured acceleration of the car 11 to the control device 30. As will be described in detail later, the control device 30 calculates the speed of the car 11 based on the measured acceleration.

[0026] The acceleration sensor 25 may be an acceleration sensor that measures acceleration in three axes. That is, the acceleration sensor 25 may measure acceleration in the X-axis, Y-axis, and Z-axis directions. Note that the X-axis, Y-axis, and Z-axis directions are perpendicular to one another. For example, if the Z-axis direction of the triaxial acceleration sensor is aligned with the movement direction (up and down) of the car 11, the car 11 does not move in the X-axis or Y-axis directions, and therefore the accelerations in the X-axis and Y-axis directions during the movement of the car 11 are close to zero. However, if the acceleration sensor 25 is malfunctioning or if the acceleration sensor 25 is misaligned, the accelerations in the X-axis or Y-axis directions may not be close to zero. In other words, by using a triaxial acceleration sensor as the acceleration sensor 25 and measuring accelerations in the X-axis and Y-axis directions, it is possible to detect malfunctions of the acceleration sensor 25 and deviations in the position of the acceleration sensor 25, such as tilts relative to the normal state.

[0027] The acceleration sensor 25 may constantly measure the acceleration of the car 11, but preferably measures the acceleration of the car 11 after the governor 13 detects that the speed of the car 11 has reached the reference speed. This shortens the operating time of the acceleration sensor 25 and reduces the memory capacity of the control device 30. As a result, the price of the control device 30 can be reduced.

[0028] The elevator system 10 further includes a control device 30 and a communication device 40. In this embodiment, the control device 30 and the communication device 40 are both disposed in the machine room 17. At least one of the control device 30 and the communication device 40 may be disposed, for example, in a pit below the elevator shaft 14. The control device 30 may also be composed of multiple devices.

[0029] The control device 30 performs overall control of the elevator device 10, including control of the movement of the car 11. The control device 30 has a memory that stores various setting information, control programs, etc., and a processor that realizes the functions of each processing unit by reading and executing the control program.

[0030] 2 , the control device 30 is connected to the speed governor 13 and the acceleration sensor 25, and acquires information necessary for control from the speed governor 13 and the acceleration sensor 25. The control device 30 is also connected to the hoisting machine 12 and the braking device 20, and is configured to transmit control signals to the hoisting machine 12 and the braking device 20. The control device 30 includes an operation control unit 31, a speed measurement unit 32, a malfunction detection unit 33, and a rescue operation unit 34.

[0031] During normal operation, the operation control unit 31 controls the hoist 12 to control the movement of the car 11. Note that normal operation means operation other than rescue operation, which will be described later. Furthermore, when the operation control unit 31 detects, based on a signal from the speed governor 13, that the speed of the car 11 has reached a reference speed, it activates the brake device 20 to stop the drive of the hoist 12.

[0032] The speed measurement unit 32 calculates the speed of the car 11 based on the measurement result of the acceleration sensor 25. The speed measurement unit 32 calculates the speed of the car 11, for example, by integrating the acceleration of the car 11 measured by the acceleration sensor 25 over time. The speed measurement unit 32 may constantly measure the speed of the car 11, but measures the speed of the car 11 at least when the control device 30 acquires a signal from the governor 13 detecting that the speed of the car 11 has reached a reference speed (hereinafter referred to as an "overspeed detection signal"), and while a rescue operation is being performed.

[0033] The malfunction detection unit 33 determines whether the speed governor 13 has malfunctioned. As described above, when the speed of the car 11 reaches the reference speed, the speed governor 13 detects that the speed of the car 11 has reached the reference speed by the pendulum hitting the electric switch 24. However, the speed governor 13 may activate the electric switch 24, for example, when solid oil adhering to the speed governor rope 21 comes into contact with the electric switch 24. Furthermore, if a foreign object gets into the support part of the pendulum, the electric switch 24 may activate even when the speed of the car 11 has not reached the reference speed. In other words, the electric switch 24 may activate even when the speed of the car 11 has not reached the reference speed.

[0034] Therefore, the malfunction detection unit 33 compares the speed of the car 11 measured by the speed measurement unit 32 at the time when the control device 30 acquires the overspeed detection signal with a predetermined reference speed. If the speed of the car 11 measured by the speed measurement unit 32 is smaller than the reference speed, it is determined that an overspeed has not actually occurred and therefore a malfunction of the speed governor 13 has occurred. On the other hand, if the speed of the car 11 measured by the speed measurement unit 32 is equal to or greater than the reference speed, it is determined that an overspeed has actually occurred and therefore therefore a malfunction of the speed governor 13 has not occurred.

[0035] The malfunction detection unit 33 may determine that the governor 13 has malfunctioned at the time when the control device 30 acquires the overspeed detection signal, or may determine that the governor 13 has malfunctioned after the brake device 20 has been activated and the car 11 has completely stopped.

[0036] When the malfunction detection unit 33 detects a malfunction of the governor 13, the rescue operation unit 34 moves the car 11 to the landing position of the nearest floor and performs rescue operation. More specifically, when the malfunction detection unit 33 detects a malfunction of the governor 13, the rescue operation unit 34 shorts and disables the circuit of the safety device including the electric switch 24 provided in the governor 13, releases the brake device 20, and drives the hoisting machine 12 to perform rescue operation.

[0037] Here, the rescue operation unit 34 performs rescue operation while measuring the speed of the car 11 using the speed measurement unit 32. Then, during rescue operation, if the speed measurement unit 32 detects that the speed of the car 11 has reached an abnormal speed, the rescue operation unit 34 activates the brake device 20 again and stops the drive of the hoist 12. That is, during normal operation, as described above, the speed of the car 11 is monitored by the governor 13, but during rescue operation, the speed of the car 11 is monitored by the speed measurement unit 32, not by the malfunctioning governor 13. Note that the abnormal speed is a speed at which it is determined that the car 11 needs to be stopped from a safety perspective, and may be the same as or different from the reference speed. As a result, even during rescue operation, if it is detected that the speed of the car 11 has reached an abnormal speed, the brake device 20 can be activated, and rescue operation can be performed while ensuring the safety of passengers.

[0038] When performing rescue operation, the rescue operation unit 34 may perform the rescue operation based on information from a monitoring center 2 provided in a remote location. For example, when the malfunction detection unit 33 detects a malfunction of the speed governor 13, the control device 30 transmits information about the malfunction of the speed governor 13 to the monitoring center 2 via the communication device 40. Then, when the control device 30 acquires information about the rescue operation from the monitoring center 2 via the communication device 40, the rescue operation unit 34 starts rescue operation based on the information. Note that, during rescue operation, when the control device 30 acquires a command to stop the rescue operation from the monitoring center 2, the rescue operation unit 34 activates the brake device 20 to stop the drive of the hoist 12.

[0039] The communication device 40 is a device for communicating with the monitoring center 2 provided in a remote location and transmitting the operation status of the elevator device 10 to the monitoring center 2. The communication device 40 is connected to the control device 30 by wire or wirelessly.

[0040] When the control device 30 acquires the overspeed detection signal, the communication device 40 transmits information to the monitoring center 2 informing that the speed of the car 11 has reached the reference speed. The communication device 40 also transmits the detection result of the malfunction detection unit 33 to the monitoring center 2. When transmitting the detection result of the malfunction detection unit 33 to the monitoring center 2, the communication device 40 may also transmit information on the speed of the car 11 measured by the speed measurement unit 32 to the monitoring center 2.

[0041] Furthermore, the communication device 40 may acquire information from the monitoring center 2 and transmit the information to the control device 30. Examples of information acquired from the monitoring center 2 include a command to start a rescue operation and information regarding the speed and destination of the car 11 during the rescue operation.

[0042] Next, the processing procedure of the elevator system 1 of this embodiment will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the operation of the elevator system 1, and illustrates the processing procedure of the control device 30. Here, a case where the control device 30 performs rescue operation without receiving a command from the monitoring center 2 will be illustrated.

[0043] As shown in Fig. 3, the control device 30 receives from the speed governor 13 a signal (overspeed detection signal) indicating that the speed of the car 11 has reached a reference speed V1 (step S1: Yes). Then, the control device 30 starts acquiring the acceleration of the car 11 from the acceleration sensor 25 from the time the overspeed detection signal is acquired (step S2). Immediately thereafter, the control device 30 activates the brake device 20 and stops the drive of the hoist 12 (step S3). The control device 30 acquires the acceleration of the car 11 from the acceleration sensor 25 until the drive of the hoist 12 is stopped and the movement of the car 11 is completely stopped. When activating the brake device 20, the control device 30 may notify passengers that the car 11 will stop via a monitor, speaker, or the like provided inside the car 11.

[0044] The control device 30 then calculates the speed of the car 11 at the time the overspeed detection signal was acquired using the acquired acceleration data of the car 11 (step S4). Then, in step S5, the control device 30 compares the calculated speed with a predetermined reference speed V1 to determine whether the speed governor 13 has malfunctioned. If the calculated speed is lower than the reference speed V1, the control device 30 determines that the speed governor 13 has malfunctioned (step S5: Yes). On the other hand, if the calculated speed is equal to or higher than the reference speed V1, i.e., if the speed governor 13 has not malfunctioned (step S5: No), an overspeed has actually occurred, which may indicate some abnormality in the elevator device 10. Therefore, since it is difficult to perform rescue operations from step S6 to step S11 described below while ensuring the safety of passengers, this flow is terminated.

[0045] Next, if the malfunction is in the governor 13, the control device 30 performs rescue operation (step S6). More specifically, the control device 30 shorts and disables the circuit of the safety device including the electric switch 24, and then releases the brake device 20. Then, by controlling the drive of the hoisting machine 12, the car 11 is moved to the landing position of the nearest floor. When performing rescue operation, passengers may be notified that rescue operation is starting via a monitor, speaker, etc. provided inside the car 11.

[0046] During the rescue operation, the control device 30 acquires the acceleration of the car 11 from the acceleration sensor 25 (step S7). Then, based on the acquired acceleration of the car 11, it calculates the speed of the car 11 during the rescue operation (step S8).

[0047] Next, in step S9, the calculated speed is compared with a predetermined abnormal speed V2. If the calculated speed is less than the abnormal speed V2 (step S9: Yes), rescue operation is being performed normally, and rescue operation is continued. On the other hand, if the calculated speed is equal to or greater than the abnormal speed V2, overspeeding has occurred during rescue operation. Therefore, the control device 30 activates the brake device 20 (step S10) and stops rescue operation.

[0048] During rescue operation, if the speed of the car 11 is less than the abnormal speed V2, the control device 30 determines in step S11 whether the rescue operation is completed, i.e., whether the car 11 has moved to the landing position of the nearest floor. If the rescue operation is not completed (step S11: No), the control device 30 returns to step S7 and continues the rescue operation while monitoring the speed of the car 11. On the other hand, if the rescue operation is completed (step S11: Yes), this flow ends.

[0049] Second Embodiment Next, an elevator system 1 including an elevator apparatus 10 according to a second embodiment will be described in detail with reference to Figures 4 and 5. Note that in the second embodiment, descriptions of the same effects and modifications as those in the first embodiment will be omitted, and the same configurations as those in the first embodiment will be denoted by the same reference numerals as those in the first embodiment, and descriptions thereof will be omitted.

[0050] Fig. 4 is a diagram schematically showing an example of an actual change in speed of the car 11 when the speed governor 13 detects that the car 11 is overspeeding and the brake device 20 is activated. Fig. 5 is a flowchart showing the operation of the elevator system 1 of this embodiment, illustrating the processing procedure of the control device 30. As will be described in detail later, in this embodiment, the method of calculating the speed of the car 11 by the speed measurement unit 32 differs from that of the first embodiment.

[0051] As shown in Figure 4, when the brake device 20 is activated, the car 11 decelerates and eventually comes to a complete stop. However, if the zero point of the acceleration sensor 25 is different from the normal state, the acceleration sensor 25 may detect the acceleration of the car 11 even though the car 11 is completely stopped. Also, if the zero point of the acceleration sensor 25 is different from the normal state, the acceleration sensor 25 may detect the car 11 as having stopped even though the car 11 is moving. In such cases, it is difficult to accurately determine whether the speed governor 13 is malfunctioning, and therefore it is necessary to correct the zero point of the acceleration sensor 25.

[0052] 5 shows a processing procedure of the control device 30 that takes into consideration the correction of the zero point of the acceleration sensor 25. As in the flow shown in FIG. 3, this illustrates an example in which the control device 30 performs rescue operation without receiving a command from the monitoring center 2.

[0053] 5, the control device 30 receives from the speed governor 13 a signal (overspeed detection signal) indicating that the speed of the car 11 has reached the reference speed V1 (step S21: Yes). Then, the control device 30 starts obtaining the acceleration of the car 11 from the acceleration sensor 25 from the time the overspeed detection signal is received (step S22). Immediately thereafter, the control device 30 activates the brake device 20 to stop the drive of the hoist 12 (step S23). The control device 30 continues to obtain the acceleration of the car 11 from the acceleration sensor 25 until the drive of the hoist 12 is stopped and the movement of the car 11 is completely stopped.

[0054] The complete stop of the car 11 is determined when a specified time has elapsed since the brake device 20 was activated. Alternatively, the determination may be made when the value of the acceleration sensor 25 remains within a specified amount of change for a certain period of time, or may be made by a rotational position sensor (not shown) provided on the hoist 12. The control device 30 obtains, as an offset value, the time from when the complete stop of the car 11 is obtained from the rotational position sensor to when the zero point is obtained from the acceleration sensor 25 (step S24).

[0055] Then, in step S25, it is determined whether the acquired offset value is within a predetermined range. If the acquired offset value is not within the predetermined range (step S25: No), that is, if a certain amount of acceleration is detected even though the car 11 is stopped, there is a possibility that an abnormality has occurred in the acceleration sensor 25. Therefore, since it is difficult to perform rescue operation while ensuring the safety of passengers, this flow is terminated. Note that if there is a possibility that an abnormality has occurred in the acceleration sensor 25, the control device 30 may transmit information informing the monitoring center 2 of the abnormality.

[0056] On the other hand, if the acquired offset value is within the predetermined range (step S25: Yes), the acceleration data of the car 11 at the time when the overspeed detection signal was acquired is offset corrected based on the offset value. Then, the speed of the car 11 at the time when the overspeed detection signal was acquired is calculated based on the acceleration data after the offset correction (step S26).

[0057] 3 , the control device 30 compares the calculated speed with a predetermined reference speed V1 to determine whether the governor 13 has malfunctioned (step S27). If the calculated speed is lower than the reference speed V1, the control device 30 determines that the governor 13 has malfunctioned (step S27: Yes). On the other hand, if the calculated speed is equal to or higher than the reference speed V1 (step S27: No), i.e., if the governor 13 has not malfunctioned, an overspeed actually occurred, and the control device 30 ends this flow.

[0058] Next, if the speed governor 13 malfunctions, the control device 30 performs rescue operation (step S28). During rescue operation, the car 11 may be operated at a speed lower than that during normal operation so that it can be stopped immediately if any abnormality occurs. During rescue operation, the control device 30 acquires the acceleration of the car 11 from the acceleration sensor 25 (step S29). Then, based on the acquired acceleration of the car 11, the control device 30 calculates the speed of the car 11 during rescue operation (step S30). At this time, it is preferable to calculate the speed of the car 11 after performing offset correction based on the offset value acquired in step S24. This allows the speed of the car 11 to be calculated accurately. As a result, rescue operation can be performed while further ensuring the safety of passengers.

[0059] Next, in step S31, the calculated speed is compared with an abnormal speed V2 corresponding to a predetermined speed of the car 11 during rescue operation. If the calculated speed is less than the abnormal speed V2 (step S31: Yes), rescue operation is being performed normally, and rescue operation is continued. On the other hand, if the calculated speed is equal to or greater than the abnormal speed V2, overspeeding has occurred during rescue operation. Therefore, the control device 30 activates the brake device 20 (step S32) and stops rescue operation.

[0060] During rescue operation, if the speed of the car 11 is less than the abnormal speed V2, the control device 30 determines in step S33 whether the rescue operation is completed, i.e., whether the car 11 has moved to the landing position of the nearest floor. If the rescue operation is not completed (step S33: No), the process returns to step S29, and the rescue operation is continued while monitoring the speed of the car 11. On the other hand, if the rescue operation is completed (step S33: Yes), this flow ends.

[0061] [Third Embodiment] Next, an elevator system 1 including an elevator apparatus 10 according to a third embodiment will be described in detail with reference to Figures 6 and 7. Note that in the third embodiment, descriptions of the same effects and modifications as those in the first embodiment will be omitted, and the same configurations as those in the first embodiment will be denoted by the same reference numerals as those in the first embodiment, and descriptions thereof will be omitted.

[0062] Fig. 6 is a block diagram showing the configuration of the elevator system 1 of this embodiment. Fig. 7 is a flowchart showing the operation of the elevator system 1 of this embodiment, illustrating the processing procedure of the control device 30. In this embodiment, the acceleration sensor 25 is an acceleration sensor that measures acceleration in three axial directions.

[0063] As shown in FIG. 6 , in this embodiment, the control device 30 includes an abnormality detection unit 35 in addition to a running control unit 31 , a speed measurement unit 32 , a malfunction detection unit 33 , and a rescue operation unit 34 .

[0064] The abnormality detection unit 35 detects an abnormality in the acceleration sensor 25 based on the values ​​measured by the acceleration sensor 25. More specifically, the abnormality detection unit 35 detects an abnormality in the acceleration sensor 25 when, among the accelerations in the three axial directions measured by the acceleration sensor 25, the acceleration in the direction perpendicular to the movement direction (up and down direction) of the car 11 is greater than a predetermined value. For example, if the Z-axis of the three-axis acceleration sensor is arranged so that it is the up and down direction, the accelerations in the X-axis and Y-axis directions during movement of the car 11 should be close to zero. Therefore, the abnormality detection unit 35 determines that an abnormality has occurred in the acceleration sensor 25 when the accelerations in the X-axis and Y-axis directions are equal to or greater than the predetermined value.

[0065] 7 shows a processing procedure of the control device 30 taking into consideration abnormality detection of the acceleration sensor 25. As with the flow shown in FIG. 3, this illustrates a case where the control device 30 performs rescue operation without receiving a command from the monitoring center 2. In this embodiment, the Z-axis direction of the three-axis acceleration sensor is arranged to coincide with the direction of movement of the car 11.

[0066] 7, the control device 30 acquires from the speed governor 13 a signal (overspeed detection signal) indicating that the speed of the car 11 has reached the reference speed V1 (step S41: Yes). Then, the control device 30 starts acquiring the acceleration of the car 11 from the acceleration sensor 25 from the time the overspeed detection signal is acquired (step S42). Immediately thereafter, the control device 30 activates the brake device 20 to stop the drive of the hoist 12 (step S43). The control device 30 acquires the acceleration of the car 11 from the acceleration sensor 25 until the drive of the hoist 12 is stopped and the movement of the car 11 is completely stopped.

[0067] The control device 30 then calculates the speed of the car 11 at the time the overspeed detection signal was acquired using the acquired acceleration data of the car 11 (step S44). Then, in step S45, the control device 30 compares the calculated speed with a predetermined reference speed V1 to determine whether the speed governor 13 has malfunctioned. If the calculated speed is lower than the reference speed V1, the control device 30 determines that the speed governor 13 has malfunctioned (step S45: Yes). On the other hand, if the calculated speed is equal to or higher than the reference speed V1, i.e., if the speed governor 13 has not malfunctioned (step S45: No), an overspeed actually occurred, and the flow ends.

[0068] Next, if there is a malfunction of the speed governor 13, the control device 30 performs rescue operation (step S46). Then, during the rescue operation, the control device 30 acquires the acceleration of the car 11 in the three axial directions from the acceleration sensor 25 (step S47).

[0069] Next, in step S48, it is determined whether the acceleration in the directions (X-axis direction and Y-axis direction) perpendicular to the moving direction (Z-axis direction) of the car 11 is equal to or less than a predetermined value. If the acceleration in the X-axis direction and Y-axis direction is equal to or less than the predetermined value (step S48: Yes), no abnormality has occurred in the acceleration sensor 25, and the process proceeds to step S49. On the other hand, if the acceleration in the X-axis direction and Y-axis direction is greater than the predetermined value (step S48: No), an abnormality such as misalignment of the acceleration sensor 25 may occur. Therefore, it is difficult to perform rescue operation while ensuring the safety of passengers. Therefore, the brake device 20 is activated to stop rescue operation (step S51). Note that if there is a possibility that an abnormality has occurred in the acceleration sensor 25, the control device 30 may transmit information informing the monitoring center 2 of the abnormality.

[0070] Next, in step S49, the control device 30 calculates the speed of the car 11 during rescue operation based on the acceleration acquired from the acceleration sensor 25. Note that the control device 30 may calculate the speed of the car 11 using only the acceleration in the Z-axis direction, or may calculate the speed of the car 11 by calculating a composite acceleration from the accelerations in the X-axis, Y-axis, and Z-axis directions and integrating the composite acceleration over time. In this case, even if the Z-axis direction of the acceleration sensor 25 does not strictly coincide with the up-down direction, the speed of the car 11 can be accurately calculated. Note that the subsequent flow is the same as the flow of the first embodiment shown in FIG. 3.

[0071] The above-described embodiment may be appropriately modified in design without impairing the objectives of the present disclosure. For example, in the above-described embodiment, the speed of the car 11 is measured based on the measurement value of the acceleration sensor 25 provided in the car 11, but this is not limited thereto. For example, a magnetic tape or ID tape whose magnetic field or brightness changes periodically may be provided on the side of the elevator shaft 14, and a position sensor serving as a reading device for reading the tape may be provided on the car 11 to detect the position of the car 11. The speed of the car 11 may then be calculated using time differentiation based on information about the detected position. Alternatively, an encoder-type rotational position sensor may be provided in the speed governor 13, and the speed of the car 11 may be calculated using time differentiation based on output information from the rotational position sensor. Alternatively, a rail may be provided on the side of the elevator shaft 14, and a roller that moves in synchronization with the car 11 may be pressed against the rail and rotated, the rotational position of which may be detected by an encoder-type rotational position sensor, and the speed of the car 11 may be calculated from the output of the rotational position sensor. Alternatively, a speed sensor may be provided that measures the speed of the car 11 from the output of each of the position sensors, and the measurement value of the speed sensor may be output to the control device 30. In this case, the speed measurement unit 32 that measures the speed of the car 11 when the overspeed detection unit detects that the speed of the car 11 has reached the reference speed may be composed of the speed sensor and a speed acquisition unit that is provided in the control device 30 and acquires the measurement value of the speed sensor.

[0072] Furthermore, in the above embodiment, the elevator device 10 includes one acceleration sensor 25, but may include multiple acceleration sensors 25. The control device 30 may calculate the speed of the car 11 using the average or median of the accelerations of the car 11 measured by the multiple acceleration sensors 25. This can improve the accuracy of measuring the speed of the car 11.

[0073] Furthermore, during rescue operation, if the variation in the measurement values ​​of the multiple acceleration sensors 25 (e.g., the difference between the maximum and minimum values) is equal to or greater than a predetermined value, the control device 30 may activate the brake device 20 and stop the rescue operation. If the variation in the measurement values ​​of the multiple acceleration sensors 25 is equal to or greater than a predetermined value, an abnormality may have occurred in the acceleration sensor 25. Therefore, by stopping the rescue operation in the above case, passenger safety can be further ensured. Similarly, if multiple position sensors or speed sensors are provided and the variation in the measurement values ​​of the multiple position sensors or speed sensors is equal to or greater than a predetermined value, the control device 30 may activate the brake device 20 and stop the rescue operation.

[0074] Furthermore, in the above embodiment, the electric switch 24 provided in the speed governor 13 detects that the speed of the car 11 has reached the reference speed, but this is not limiting. For example, an optical or magnetic rotational position sensor may be provided in the speed governor 13 to detect the rotation angle of the speed governor 13, and based on the change in the rotation angle over time, it may be detected that the speed of the car 11 has reached the reference speed. Furthermore, as a configuration for detecting that the speed of the car 11 has reached the reference speed, the electric switch 24 and the rotational position sensor provided in the speed governor 13 may be used in combination.

[0075] In addition, a camera, a sensor, or the like may be provided inside the car 11 to detect the presence or absence of passengers, and rescue operation may be performed only when there is a passenger inside the car 11. In other words, if there is no passenger inside the car 11, a malfunction of the governor 13 may not be detected, and rescue operation may not be performed.

[0076] REFERENCE SIGNS LIST 1 elevator system, 2 monitoring center, 10 elevator device, 11 car, 12 hoisting machine, 13 governor, 14 elevator shaft, 15 car door, 16 landing door, 17 machine room, 18 main rope, 19 counterweight, 20 brake device, 21 governor rope, 22 governor wheel, 23 tension wheel, 24 electric switch, 25 acceleration sensor, 30 control device, 31 operation control unit, 32 speed measurement unit, 33 malfunction detection unit, 34 rescue operation unit, 35 abnormality detection unit, 40 communication device

Claims

1. An elevator device comprising: a car that moves in an elevator shaft; an operation control unit which controls the movement of the car; an overspeed detection unit which detects when the speed of the car has reached a reference speed; a braking unit which applies a braking force to the movement of the car when the overspeed detection unit detects that the speed of the car has reached the reference speed; a malfunction detection unit which detects a malfunction of the overspeed detection unit; a speed measurement unit which measures the speed of the car when the overspeed detection unit detects that the speed of the car has reached the reference speed; and a rescue operation unit which performs rescue operation while measuring the speed of the car using the speed measurement unit when the malfunction detection unit detects a malfunction of the overspeed detection unit, wherein during rescue operation, when the speed measurement unit detects that the speed of the car has reached an abnormal speed, a braking force is applied to the movement of the car by the braking unit.

2. An elevator device as described in claim 1, wherein if the speed of the car measured by the speed measurement unit is lower than the reference speed at the time when the overspeed detection unit detects that the speed of the car has reached the reference speed, the malfunction detection unit determines that the overspeed detection unit has malfunctioned.

3. An elevator device as described in claim 1, wherein the speed measurement unit measures the speed of the car from the point in time when the overspeed detection unit detects that the speed of the car has reached the reference speed.

4. The elevator device according to claim 1, wherein the speed measurement unit measures the speed of the car based on information from an acceleration sensor.

5. The elevator device according to claim 1, wherein the speed measurement unit measures the speed of the car based on information from an acceleration sensor that measures acceleration in three axial directions.

6. The elevator device according to claim 5, wherein the speed measurement unit calculates a composite acceleration from the accelerations in the three axial directions measured by the acceleration sensor, and measures the speed of the car based on the composite acceleration.

7. The elevator device of claim 5, further comprising an abnormality detection unit that detects an abnormality in the acceleration sensor based on an acceleration in a direction perpendicular to the moving direction of the car among the accelerations in three axial directions measured by the acceleration sensor, and when an abnormality in the acceleration sensor is detected by the abnormality detection unit during rescue operation, a braking force is applied to the movement of the car by the braking unit.

8. The elevator device according to claim 1, wherein the speed measurement unit measures the speed of the car based on information from a plurality of sensors which are a plurality of acceleration sensors, speed sensors or position sensors.

9. An elevator device as described in claim 8, wherein, during rescue operation, if the variation in the measurement values ​​of the multiple sensors is equal to or greater than a predetermined value, the braking unit applies a braking force to the movement of the car.

10. The elevator apparatus according to claim 1, wherein the speed of the car during rescue operation is slower than the speed of the car during normal operation.

11. An elevator apparatus as described in claim 1, further comprising a communication device capable of communicating with a monitoring center for remote monitoring, wherein the rescue operation unit performs rescue operation based on instructions from the monitoring center.

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