Elevator safety system

Abstract

To provide an elevator safety system that can improve the reliability of safety features. [Solution] The elevator safety system is designed to bring the elevator car to an emergency stop when it detects an abnormality in the operating condition of the elevator car (20) which is operated by an operation control system including an elevator control device (1). The safety system comprises a brake device (33) installed on the elevator car that grips a guide rail (50) to brake the elevator car, a position detector (31) that detects information regarding the position of the elevator car in the hoistway, and a safety control device (40) that detects the position and speed of the elevator car in the hoistway based on the information detected by the position detector, and activates the brake device when it detects an abnormality in the operating condition of the elevator car based on the detected position and speed, and is independent of the operation control system.

Description

[Technical Field]

[0001] This invention relates to an elevator safety system that determines whether or not there is an abnormality in the operation of the elevator car, and if an abnormality is determined to be present, brings the elevator car to an emergency stop. [Background technology]

[0002] In recent years, the electronic nature of safety systems in elevators has been progressing.

[0003] In an electronic safety system, a safety controller equipped with a logic judgment circuit such as a microcomputer detects an abnormality in the operation of the elevator car based on the detected position and speed of the car, and then sends a command signal to instruct the elevator car to stop or decelerate.

[0004] The safety controller has multiple safety functions depending on the software executed by the logic judgment circuit. For example, the electronic safety controller described in Patent Document 1 (Figure 5) has a limit switch function, a terminal floor forced deceleration function, an overspeed switch function, and a door open travel protection function.

[0005] Regarding prior art related to safety systems including safety controllers, the technology described in Patent Document 2 is known.

[0006] In the technology described in Patent Document 2 (Figure 2), the hoisting machine brake is connected to the power supply via a brake power cutoff device for the control controller and contacts opened and closed by a safety controller. The inverter that drives the hoisting machine motor is connected to the AC power supply via a power circuit breaker. The power circuit breaker is connected to the power supply via a drive system power cutoff device for the control controller and contacts opened and closed by a safety controller. The safety controller controls the supply of power to the power circuit breaker and the hoisting machine brake by opening and closing each contact based on input signals from a rotary encoder provided on the governor and a position detection sensor provided on the elevator car. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2016-69093 [Patent Document 2] International Publication No. 2015 / 079976 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In the conventional technology described above, when an elevator car is brought to an emergency stop, a delay occurs between the sending of a command signal from the safety controller and the stopping of the elevator car due to slippage of the main rope between the sheave of the hoisting machine and the main rope. This limits the reliability of the safety function.

[0009] Therefore, the present invention provides an elevator safety system that can improve the reliability of safety functions. [Means for solving the problem]

[0010] To solve the above problems, the elevator safety system according to the present invention is designed to make an emergency stop of an elevator car when it detects an abnormality in the operating state of the elevator car, which is operated by an operation control system including an elevator control device, and comprises a brake device provided on the elevator car that grips a guide rail to brake the elevator car, a position detector that detects information regarding the position of the elevator car in the hoistway, and a safety control device that detects the position and speed of the elevator car in the hoistway based on the information detected by the position detector, and activates the brake device when it detects an abnormality in the operating state of the elevator car based on the detected position and speed, and is independent of the operation control system. [Effects of the Invention]

[0011] According to the present invention, the reliability of the safety functions of the elevator safety system is improved.

[0012] Other issues, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing]

[0013] [Figure 1] This is an overall configuration diagram showing the elevator in Example 1. [Figure 2] This is a cross-sectional view showing an example of the configuration of the basket brake 33 (Figure 1). [Figure 3] This is a functional block diagram showing the configuration of the safety control device in Example 1. [Figure 4] This is a block diagram showing the configuration of the brake circuit in Example 1. [Figure 5] This is an overall configuration diagram showing the elevator in Example 2. [Figure 6] This is a functional block diagram showing the configuration of the safety control device in Example 2. [Figure 7] This is a position-velocity (dv) characteristic diagram showing the deceleration characteristics for speed abnormality detection in the first deceleration determination unit 44a (Figure 6). [Figure 8] This is a position-velocity (dv) characteristic diagram showing the deceleration characteristics for speed abnormality detection in the second deceleration determination unit 44b (Figure 6). [Figure 9] This is a position-velocity (dv) characteristic diagram showing the deceleration characteristics for speed abnormality detection in the second deceleration determination unit 44b (Figure 6). [Figure 10] This flowchart shows the speed abnormality detection operation of the safety control device in Example 2. [Modes for carrying out the invention]

[0014] Hereinafter, an elevator that is one embodiment of the present invention will be described with reference to the drawings, using Examples 1 and 2. In each figure, elements with the same reference number indicate the same or similar functional elements. [Examples]

[0015] Figure 1 is an overall configuration diagram showing an elevator according to Embodiment 1 of the present invention.

[0016] The elevator car 20 is connected to the counterweight 22 via a main rope 21 within the hoistway 200. The main rope 21 is sequentially wound around an elevator car pulley 103 located at the bottom of the elevator car 20, a direction-changing pulley 102 located at the top of the hoistway 200, a sheave provided by the hoisting machine, and a counterweight pulley 101. Both ends of the main rope 21 are fixed to the top of the hoistway 200.

[0017] When power is supplied to the motor 3 of the hoisting machine by the power converter in the elevator control device 1, the motor 3 rotates the sheave. As the main rope 21 is driven by the rotating sheave, the elevator car 20 moves between multiple floors within the hoistway 200, guided by the guide rail 50. In this case, the counterweight 22 moves in the opposite direction to the elevator car 20, guided by the counterweight guide rail (not shown). A buffer 23 is provided at the bottom of the hoistway 200, i.e., the pit, to catch the elevator car 20 when it descends beyond the terminal floor (lowest floor).

[0018] A pulse generator, which is a motion detector 60, is attached to the motor 3. In this embodiment 1, a rotary encoder is used as the motion detector 60. The elevator control device 1 counts the pulses generated by the motion detector 60 in accordance with the rotation of the motor 3. The elevator control device 1 calculates the position of the elevator car 20 by accumulating the amount of movement of the elevator car 20 based on the counting of the pulses. The elevator control device 1 also calculates the speed of the elevator car 20 based on the amount of movement of the elevator car 20. The elevator control device 1 controls the operation of the elevator car 20 by controlling the motor 3 based on the calculated position and speed of the elevator car 20.

[0019] Furthermore, the elevator control device 1 opens the contacts of the electromagnetic contactor 2 to protect the motor 3, thereby cutting off the power supply from the building's power source 4.

[0020] The elevator car 20 is equipped with an elevator car side door 25 that engages with the landing side door 24 and is opened and closed together with the landing side door 24 by a door drive device provided in the elevator car 20, and a position detector 26. The position detector detects objects to be detected 27 that are located adjacent to each floor within the elevator shaft.

[0021] When the elevator control device 1 detects the object to be detected 27, it determines that the elevator car 20 has reached the floor corresponding to the object to be detected 27. In this case, if the floor corresponding to the object to be detected is a stopping floor, the elevator control device 1 brings the elevator car 20 to the floor. The elevator control device 1 also corrects the position calculated by counting pulses to the position of the floor corresponding to the object to be detected 27.

[0022] When the elevator car 20 is to land, the elevator control device 1 aligns the floor surface of the elevator car 20 with the floor surface of the landing, and then controls the hoisting machine brake 5 to mechanically brake the hoisting machine so that it does not move.

[0023] The position (d) of the elevator car 20 represents the height from the reference position within the hoistway 200 (in Example 1, the landing floor of the reference floor (lowest floor)) to the reference part of the elevator car 20 (in Example 1, the elevator car floor). In other words, the position of the elevator car represents its absolute position within the hoistway 200.

[0024] Furthermore, the position of each floor is represented by the height from the landing surface of the lowest floor to the landing surface of each floor (for example, the position of the lowest floor is "0 (zero)"). Therefore, when elevator car 20 is at rest, the position of elevator car 20 is equal to the position of the floor.

[0025] In Embodiment 1, the safety system includes a safety control device 40, an absolute position detector 31, a detected object 32 having absolute position information within the elevator shaft 200, a car brake 33, and an emergency stop device 34.

[0026] The detected object 32 has a long, rectangular shape (for example, tape-like, rope-like, ribbon-like, or elongated rod-like) and is continuously installed from the top to the bottom of the elevator shaft 200.

[0027] The safety control device 40, the absolute position detector 31, and the car brake 33 are located on the upper part of the elevator car 20. The emergency stop device 34 is located on the lower part of the elevator car 20.

[0028] When the absolute position detector 31 detects the absolute position information of the object to be detected 32, the safety control device 40 detects the position (d) of the elevator car 20 within the elevator shaft 200 based on the detection signal from the absolute position detector 31. The safety control device 40 also detects the speed of the elevator car 20 based on the time change of the detected position (d) of the elevator car 20.

[0029] The detected object 32 has its longitudinal direction aligned with the height direction within the elevator shaft, extending from the top to the bottom of the elevator shaft 200. Absolute position information is continuously set for the detected object 32 from the part located at the top of the elevator shaft to the part located at the bottom of the elevator shaft and the portion in between. This allows for the continuous detection of the elevator car 20's position (d) and speed within the range of its movement.

[0030] The absolute position information of the detected object 32 is set on the detected object 32 by making its electromagnetic characteristics, optical characteristics, mechanical shape and properties, and surface geometric pattern shape different along the longitudinal direction of the detected object 32. In contrast, the absolute position detector 31 that detects the absolute position information of the detected object 32 can be a magnetic sensor, an optical sensor, an image sensor, etc. Alternatively, the detected object 32 may be made of magnetic wires, and the position (d) and speed of the elevator car 20 may be detected by detecting magnetostrictive vibration pulses propagating through the magnetic wires using the absolute position detector 31 (for example, a magnetic sensor).

[0031] Based on the detected position (d) and speed of the elevator car 20, the safety control device 40 determines that there is an abnormality in the operating state of the elevator car 20, and activates the elevator car brake 33 or the emergency stop device 34 to bring the elevator car 20 to an emergency stop.

[0032] The emergency stop device 34 has a configuration based on known technology. For example, the emergency stop device 34 uses a wedge effect to press a braker (not shown) against the guide rail 50, thereby bringing the elevator car 20 to a sudden stop by frictional force. However, in Embodiment 1, the emergency stop device 34 transitions to a braking state when an electric operating device (not shown) located at the bottom of the elevator car 20 is activated, instead of the governor device. When the safety control device 40 determines that the descending speed of the elevator car 20 has exceeded the rated speed and reached a predetermined value (for example, a speed value not exceeding 1.4 times the rated speed), it activates the electric operating device to activate the emergency stop device 34.

[0033] Figure 2 is a cross-sectional view showing an example configuration of the basket brake 33 (Figure 1). In Figure 2, the basket brake 33 is in a standby state, i.e., a non-braking state.

[0034] In Example 1, the basket brake 33 has a left-right symmetrical configuration with respect to the center line C1 as the axis of symmetry, and a vertically symmetrical configuration with respect to the center line C2 as the axis of symmetry, as shown in Figure 2.

[0035] The cage brake 33 illustrated in Figure 2 mainly consists of an electromagnet section in which a coil 302 is wound around a magnetic core 301, a spring 303, a magnetic material adsorbent 304 which is attracted to the electromagnet section when excited, a brake shoe 306 which faces the guide rail 50 and is supported by the adsorbent 304, and a frame 300 which holds these components.

[0036] When the coil 302 is energized and the electromagnet is energized, the magnetic force causes the attractor 304 to be attracted to the electromagnet against the elastic force of the spring 303. As a result, the brake shoe 306 separates from the guide rail 50, and the cage brake 33 enters a standby state.

[0037] When the power to coil 302 is cut off and the electromagnet is demagnetized, the electromagnetic force disappears, and the adsorbent 304 moves toward the guide rail 50, guided by the elastic force of spring 303 and directed toward guide rail 50. As a result, the brake shoe 306 is pressed against the guide rail 50, and the cage brake 33 enters a braking state. In this embodiment 1, the guide rail 50 is gripped by two brake shoes 306 located on both the left and right sides of the guide rail 50.

[0038] The car brake 33 is installed on the elevator car 20 and, as described above, generates braking force by gripping the guide rail 50 with the brake shoe 306. Therefore, the braking force from the car brake 33 acts directly on the elevator car 20. As a result, the elevator car 20 is stopped within a braking distance corresponding to the braking force, without being affected by the slippage of the main rope 21.

[0039] In Figure 2, the brake shoe 306 is supported by the suction body 304 via a support member 307 and a spring 308 inserted through the support member 307. As a result, even if the elevator car 20 is displaced vertically after it has stopped, the brake shoe 306 maintains its grip on the guide rail.

[0040] Furthermore, the brake shoe 306 may be attracted to the electromagnet without using the adsorbent 304 that supports the brake shoe 306.

[0041] The cage brake 33 is not limited to the configuration shown in Figure 2; various braking devices that generate braking force by pressing the brake shoe against the guide rail or gripping the guide rail with the brake shoe can be applied. Known cage brakes and rail brakes may also be used.

[0042] Figure 3 is a functional block diagram showing the configuration of the safety control device 40 in Embodiment 1.

[0043] The safety control device 40 includes a position / speed detection unit 41, an abnormality detection unit 42, and a power cut-off unit 43. The abnormality detection unit 42 includes a terminal floor forced deceleration function unit 44.

[0044] In Embodiment 1, the safety control device 40 includes a computer system such as a microcomputer, and the computer system operates as a unit by executing a predetermined program.

[0045] Furthermore, the elevator control device 1 (Figure 1) is also equipped with an independent computer system such as a microcomputer, and the computer system controls the operation of the elevator car 20 by executing a predetermined program.

[0046] The position and speed detection unit 41 detects the position d and speed v of the elevator car 20 based on the absolute position information of the object to be detected 32 (Figure 1), which is detected by the absolute position detector 31.

[0047] The abnormality detection unit 42 determines whether there is an abnormality in the operating state of the elevator car 20 based on the position d and speed v of the elevator car 20 detected by the position and speed detection unit 41. If the abnormality detection unit 42 determines that there is an abnormality, it generates an abnormality detection signal.

[0048] The abnormality detection unit 42 has multiple safety function units depending on the operating state for which the abnormality is to be detected. Among them, Figure 3 shows the terminal floor forced deceleration function unit 44.

[0049] The terminal floor forced deceleration function unit 44 sets a speed threshold V near the terminal floor, depending on the position of the elevator car 20. th The speed v of the elevator car 20 is set in advance, and the position d of the elevator car 20 is set to V th Determine if it exceeds V. Terminal floor forced deceleration function unit 44 determines if v is V th If it is determined that the value exceeds a certain limit, an abnormality detection signal is generated, indicating that there is an abnormality in the operating state.

[0050] The abnormality detection unit 42 also includes an overspeed switch function unit (not shown) as a safety function unit. When the overspeed switch function unit determines that the lifting speed of the elevator car 20 has exceeded the rated speed and reached a predetermined value (for example, a speed value not exceeding 1.3 times the rated speed), it determines that there is an abnormality (overspeed) in the operating state and generates an abnormality detection signal.

[0051] The abnormality detection unit 42 may also include a limit switch function unit and a door-open driving protection function unit (see Patent Document 1 above) as safety function units.

[0052] When the power cut-off unit 43 receives an abnormality detection signal generated by the abnormality detection unit 42, it sends a power cut-off command signal S to cut off the power to the cage brake 33. C * Send it out.

[0053] Figure 4 is a block diagram showing the configuration of the brake circuit in Example 1.

[0054] The upper figure shows the configuration of the brake circuit that operates the cage brake 33 in the safety system of Embodiment 1. The lower figure shows the configuration of the brake circuit that operates the hoisting machine brake 5 in the operation control system of Embodiment 1.

[0055] As shown in the figure above, the basket brake 33 is connected to the power supply via the contact 52 (normally open contact) of the contactor B. The contactor circuit 51, which includes the coil of contactor B and the current supply circuit to the coil, is controlled by the safety control device 40 to switch the current ON and OFF.

[0056] The safety control device 40 controls the energization of the coil of contactor B to ON when the elevator car 20 is in a normal operating state. As a result, the contact 52 of contactor B closes, and power is supplied to the elevator car brake 33. In other words, the elevator car brake 33 is in a standby state (non-braking state).

[0057] When determining that there is an abnormality in the operating state of the car 20 based on the detection signal from the absolute position detector 31, the safety control device 40 outputs a power cutoff command signal S to cut off the power supply to the car brake 33 C * . In the contactor circuit 51, in response to the power cutoff command signal S C * , the energization to the coil of contactor B is turned OFF. As a result, the contact 52 of contactor B transitions from the closed state to the open state, so the power supply to the car brake 33 is cut off. That is, the car brake 33 transitions from the standby state (non-braking state) to the braking state.

[0058] As shown in the following figure, the hoist brake 5 is connected to the power supply via the contact 54 (normally open contact) of contactor C. The contactor circuit 53 including the coil of contactor C and the energization circuit for the coil is controlled by the elevator control device 1 to turn energization ON and OFF.

[0059] The elevator control device 1 controls the operation of the car 20 based on the respective detection signals from the movement detector 60 and the position detector 26.

[0060] When moving the car 20, the elevator control device 1 controls to turn ON the energization to the coil of contactor C. As a result, the contact 54 of contactor C enters the closed state, so power is supplied to the hoist brake 5. That is, the hoist brake 5 is in the released state (non-braking state).

[0061] When stopping the car 20, the elevator control device 1 controls to turn OFF the energization to the coil of contactor C. As a result, the contact 54 of contactor C enters the open state, so the power supply to the hoist brake 5 is cut off. That is, the hoist brake 5 transitions from the released state (non-braking state) to the activated state (braking state).

[0062] As shown in Figure 4, the safety system of Embodiment 1 includes a position detection device (absolute position detector 31, detected object 32 (Figure 1), position / speed detection unit 41 (Figure 3)), a control device (safety control device 40), a brake device (car brake 33), and a brake circuit (upper part of Figure 4), independently of the driving control system. In other words, in Embodiment 1, the safety system is separated and independent of the driving control system. Therefore, the safety system can reliably detect abnormalities in the driving state of the elevator car 20.

[0063] According to the above-described embodiment 1, when a safety system, which is configured independently of the driving control system, detects an abnormality in the driving state of the elevator car 20, it activates the elevator car brake 33, which is provided on the elevator car 20 and grips the guide rail 50 to brake the elevator car 20, thereby bringing the elevator car 20 to an emergency stop. This allows for highly reliable detection of abnormalities in the driving state of the elevator car 20 and enables high-precision emergency stopping of the elevator car 20. Therefore, the reliability of the safety system can be improved.

[0064] Furthermore, if the safety system has a terminal floor forced deceleration function, according to Example 1, the stroke of the buffer 23 (Figure 1) can be shortened to reduce the pit depth ("D1" in Figure 1). [Examples]

[0065] Figure 5 is an overall configuration diagram showing an elevator according to Embodiment 2 of the present invention.

[0066] In Embodiment 2, as in Embodiment 1, the safety system includes a safety control device 40, an absolute position detector 31, a detected object 32 having absolute position information within the elevator shaft 200, a car brake 33, and an emergency stop device 34.

[0067] Although not shown in Figure 5, the safety control device 40 in Embodiment 2 detects an abnormality in the speed of the elevator car 20 early and activates the car brake 33 to decelerate and stop the elevator car 20 at the target stopping position. The target stopping position is the terminal floor when the elevator car 20 is located near the terminal floor. When the elevator car 20 is located away from the terminal floor, the target stopping position is set according to the position of the elevator car 20. The abnormality in speed is determined based on the deceleration characteristics of the car brake 33.

[0068] As a result, as shown in Figure 5, the buffer 23 (Figure 1) is not provided in Embodiment 2. Therefore, the pit depth ("D2" in Figure 2) can be reduced. In Embodiment 2, when the elevator car 20 lands on the lowest floor, D2 can be reduced to the extent that the structure of the elevator car 20 at the bottom of the elevator car 20 (including the position detector 26, emergency stop device 34, elevator car pulley 103, and car frame not shown) fits within the pit without contacting the bottom of the pit.

[0069] Figure 6 is a functional block diagram showing the configuration of the safety control device 40 in Embodiment 2.

[0070] The safety control device 40, as in Embodiment 1 (Figure 3), includes a position / speed detection unit 41, an abnormality detection unit 42, and a power cut-off unit 43. Also, as in Embodiment 1, the abnormality detection unit 42 includes a terminal floor forced deceleration function unit 44.

[0071] In Embodiment 2, the terminal floor forced deceleration function unit 44 includes a first deceleration determination unit 44a and a second deceleration determination unit 44b that detect abnormalities in the speed of the elevator car 20 at an early stage.

[0072] The first deceleration determination unit 44a determines that the speed v of the elevator car 20 is abnormal when the elevator car 20 is located near the terminal floor (for example, between the terminal floor and the nearest floor to the terminal floor), and sets the terminal floor as the target stopping position for stopping the elevator car 20 using the car brake 33.

[0073] The first deceleration determination unit 44a determines whether there is a speed abnormality based on the position d and speed v of the elevator car 20, using the speed in the deceleration characteristics as a threshold when the elevator car 20 is decelerated by the car brake 33 toward the terminal floor.

[0074] The first deceleration determination unit 44a generates an abnormality detection signal when it determines that there is an abnormality in speed. When the power cut-off unit 43 receives the abnormality detection signal generated by the first deceleration determination unit 44a, it generates a power cut-off command signal S to cut off the power to the cage brake 33. C * Send it out.

[0075] The second deceleration determination unit 44b determines, based on the position d of the elevator car 20, that the speed v of the elevator car 20 is abnormal when the elevator car 20 is located away from the terminal floor (for example, between the nearest floor to the lowest floor and the nearest floor to the top floor), and sets a target stopping position where the elevator car 20 will be stopped by the elevator car brake 33. Therefore, the target stopping position is updated in accordance with the movement of the elevator car 20.

[0076] The second deceleration determination unit 44b estimates whether or not a speed abnormality has occurred before setting the target stopping position. In Embodiment 2, the second deceleration determination unit 44b estimates whether or not a speed abnormality has occurred based on the difference between the detected speed v and the rated speed. If the difference value is within the allowable range, the second deceleration determination unit 44b estimates that no abnormality has occurred. If the difference value is outside the allowable range, the second deceleration determination unit 44b estimates that an abnormality has occurred.

[0077] If the second deceleration determination unit 44b estimates that no abnormality has occurred, it sets the nearest position where the elevator car 20 can be stopped by braking with the elevator car brake 33, based on the position d of the elevator car 20 detected by the position and speed detection unit 41 at a given time (the present moment), as the target stopping position.

[0078] If the second deceleration determination unit 44b estimates that an abnormality has occurred, it sets the nearest position where the elevator car 20 can be stopped by braking with the elevator car brake 33, based on the position d of the elevator car 20 at the time when the onset of the abnormality is estimated to have occurred earlier than the current time, as the target stopping position.

[0079] Furthermore, it is preferable that the nearest location be the location on the nearest floor. In this case, it becomes possible to quickly carry out rescue operations for those trapped in the emergency stop and to restore service quickly.

[0080] The second deceleration determination unit 44b determines whether there is a speed abnormality based on the deceleration characteristics (dv characteristics) of the elevator car 20 when the elevator car 20 is decelerated by the elevator car brake 33 toward the target stopping position, that is, using the speed in the deceleration characteristics as a threshold, from the position d and speed v of the elevator car 20 at a given point in time (the present moment).

[0081] The second deceleration determination unit 44b generates an abnormality detection signal when it determines that there is an abnormality in speed. When the power cut-off unit 43 receives the abnormality detection signal generated by the second deceleration determination unit 44b, it generates a power cut-off command signal S to cut off the power to the cage brake 33. C * Send it out.

[0082] The braking force from the cage brake 33 acts directly on the elevator car 20, so the elevator car 20 stops at a braking distance corresponding to the braking force. Therefore, a target stopping position can be set, and the elevator car 20 can be brought to a decelerated stop.

[0083] According to the first deceleration determination unit 44a described above, an abnormality in the speed of the elevator car 20 is detected early near the terminal floor, and the elevator car 20 is decelerated and stopped with the terminal floor as the target stopping position. As a result, the entry speed of the elevator car 20 into the pit can be made almost zero. Therefore, the depth of the pit (D2) can be set to a depth such that the lower part of the elevator car 20 does not make contact, and the installation of a buffer ("23" in Figure 1) can be omitted.

[0084] Furthermore, according to the first deceleration determination unit 44a described above, when a buffer (labeled "23" in Figure 1) is provided as in Embodiment 1 (Figure 1), the stroke of the buffer can be significantly shortened, thereby reducing the pit depth.

[0085] Furthermore, according to the second deceleration determination unit 44b described above, even at a position far from the terminal floor, an abnormality in the speed of the elevator car 20 is detected early, and the elevator car 20 is decelerated and stopped at the nearest position as the target stopping position. As a result, the elevator car 20 can be brought to an emergency stop before it approaches the terminal floor. Therefore, in combination with the first deceleration determination unit 44a, the installation of buffers ("23" in Figure 1) can be reliably omitted.

[0086] As described above, even when the second deceleration determination unit 44b estimates that no abnormality has occurred, it sets a target stopping position and determines whether or not there is an abnormality in speed. This allows for early detection of an abnormality in speed when an excessive sudden change in speed occurs, enabling the elevator car 20 to be brought to an emergency stop.

[0087] Figure 7 is a position-velocity (dv) characteristic diagram showing the deceleration characteristics for speed abnormality detection in the first deceleration determination unit 44a (Figure 6). As described above, these deceleration characteristics represent the relationship between the position of the elevator car 20 and the speed threshold for speed abnormality detection.

[0088] In Figure 7, the deceleration curve 71 (solid line) shows the deceleration characteristics of the elevator car 20 due to the elevator car brake 33. The value of v at point (d,v) on the deceleration curve 71 is the speed threshold V used for determining abnormal speed at position d of the elevator car 20. th This indicates.

[0089] The deceleration curve 70 shows the deceleration characteristics of the elevator car 20 under normal operating conditions. In the figure, "V RS " represents the rated speed (the same applies to Figures 8 and 9 described later).

[0090] In deceleration curve 71, v is equal to V thHowever, as the elevator car 20 approaches the terminal floor (the lowest floor in Figure 7: d=0), which is the target stopping position, it increases to a predetermined overspeed value V according to its position d. OS It decreases from zero.

[0091] The overspeed switch function unit (not shown) of the abnormality detection unit 42 shown in Figure 6 activates when the elevator car 20's lifting speed exceeds the rated speed. OS (For example, rated speed V RS If it is determined that the speed has reached a value not exceeding 1.3 times the specified speed, an abnormality detection signal is generated, indicating an abnormality in the operating condition (overspeed).

[0092] The first deceleration determination unit 44a determines that the speed of the elevator car 20 is substantially V due to the elevator car brake 33. OS The braking distance of the elevator car 20 when it is decelerated from to zero is D. BR Therefore, elevator car 20 is at the terminal floor, and the distance from the terminal floor is D. BR It operates when it is positioned between this position and that position. In other positions, the overspeed switch function operates.

[0093] If L (=d) is the remaining distance from the position d of the elevator car 20 to the target stopping position (d=0), and α is the deceleration of the elevator car 20 due to the elevator brake 33, then the speed threshold V for determining the abnormal speed shown by the deceleration curve 71 is th This is equation (1) "V th =(2αL) 1 / 2 The first deceleration determination unit 44a determines that the speed v of the elevator car 20 at position d is calculated by equation (1). th If it is determined that v ≥ Vth, then v is judged to be abnormal and an abnormality detection signal is output. If the value of α varies, the value of α in equation (1) is taken as the average value.

[0094] Note that equation (1) "V th =(2αL) 1 / 2 Regarding ", for example, a very small collision velocity (V low ) is acceptable if "V th =(2αL+V low 2 ) 1 / 2It is also acceptable to do the following: For example, if the impact of a collision can be mitigated by slowing down to 5 m / min when reaching the lowest floor, then this may be done. Examples of such cases include installing cushioning material for low speeds under the car, laying rubber mats on the building side that can withstand low-speed collisions, or having sufficient structural strength on the building side to withstand collisions.

[0095] By determining whether or not there is an abnormality in the speed of the elevator car based on the deceleration characteristics shown by the deceleration curve 71, an abnormality in speed can be detected early, and the elevator car brake 33 can be activated to bring the elevator car 20 to an emergency stop with the terminal floor (the lowest floor in Figure 7) as the target stopping position.

[0096] Figure 8 is a position-velocity (dv) characteristic diagram showing the deceleration characteristics for speed abnormality detection in the second deceleration determination unit 44b (Figure 6). As described above, these deceleration characteristics represent the relationship between the position of the elevator car 20 and the speed threshold for speed abnormality detection.

[0097] Furthermore, the second deceleration determination unit 44b estimates that no speed abnormality has occurred. Also, the elevator car 20 is descending between the nearest floor to the lowest level and the nearest floor to the highest level.

[0098] In Figure 8, the deceleration curve 72 (solid line) shows the deceleration characteristics of the elevator car 20 due to the elevator car brake 33. The value of v at point (d,v) on the deceleration curve 72 is the speed threshold V used for determining abnormal speed at position d of the elevator car 20. th This indicates.

[0099] Note that Figure 8 also shows the aforementioned deceleration curves 70 and 71 (the same applies to Figure 9, which will be discussed later).

[0100] Point P in Figure 8 n is a moment t n The position of the elevator car 20 in t n )) and velocity v(=V RS ) indicates.

[0101] In deceleration curve 72, v is equivalent to Vth However, the target stopping position, i.e., d(t n A predetermined overspeed value V is set according to the position d of the elevator car 20, moving toward the nearest position d0 based on ). OS It decreases from zero.

[0102] The nearest position d0 is the position where, if an abnormality is detected, the elevator car 20 can be stopped by the elevator car brake 33 without overshooting. If there are no restrictions on the target stopping position, d(t) is along the direction of movement of the elevator car 20. n ) from braking distance D BR The nearest location, separated by only a certain distance, is set as the target stopping position.

[0103] If the nearest position d0 is the position of the nearest floor, then d(t n Depending on the case, as shown in Figure 8, d(t n The distance between ) and d0 is D BR It becomes larger than this. Therefore, the speed threshold V shown by the deceleration curve 72 th The basket position d is d0+D BR ~d(t n ) range (d0+D BR ≤d≦d(t n )) So, V OS Therefore, within this range, the overspeed switch function unit (not shown) operates. That is, the deceleration characteristics used by the second deceleration determination unit 44b are, in effect, when the car position d in the deceleration curve 72 is d0 to d0+D BR Range (d0≦d≦d0+D BR The part in parentheses represents the deceleration characteristics.

[0104] Furthermore, if the target stopping position is set to include positions between floors, not just the nearest floor, then d(t n ) From there, along the direction of movement of the elevator car 20, D BR It is set at a distance. In this case, the deceleration curve 72 corresponds to the curve obtained by shifting the deceleration curve 71 by d0.

[0105] Position d(t) of elevator car 20 n )(However, d0≦d(t n)≦d0+D BR The remaining distance from ) to the target stopping position (d=d0) is L(=d(t n )-d0), if α is the deceleration of the elevator car 20 due to the elevator car brake 33, then the speed threshold V for determining abnormal speed shown by the deceleration curve 72 is th Similar to the deceleration curve 71 mentioned above, equation (1) "V th =(2αL) 1 / 2 It is represented as ".

[0106] The second deceleration determination unit 44b determines that the speed v of the elevator car 20 detected by the position and speed detection unit 41 is calculated by formula (1) V th That's all (v≧V th If it is determined that v is abnormal, it is determined that v is abnormal and an abnormality detection signal is output.

[0107] Furthermore, it is presumed that no speed anomalies have occurred, so unless an excessive sudden change in speed occurs, v <V th Consequently, the second deceleration determination unit 44b does not output an abnormality detection signal.

[0108] Figure 9 is a position-velocity (dv) characteristic diagram showing the deceleration characteristics for speed abnormality detection in the second deceleration determination unit 44b (Figure 6). As described above, these deceleration characteristics represent the relationship between the position of the elevator car 20 and the speed threshold for speed abnormality detection.

[0109] Furthermore, the second deceleration determination unit 44b estimates that an abnormality in speed has occurred. Also, the elevator car 20 is descending between the nearest floor to the lowest level and the nearest floor to the highest level.

[0110] In Figure 9, the deceleration curve 72 (solid line) shows the deceleration characteristics of the elevator car 20 due to the elevator car brake 33. The value of v at point (d,v) on the deceleration curve 72 is the speed threshold V used for determining abnormal speed at position d of the elevator car 20. th This indicates.

[0111] Point P in Figure 9 n+2 , P n+1 , and P n These are each at a specific point in time (the present moment) t n+2, t n+2 a time point one step before time point t n+1 , and t n+1 a time point one step before time point t n indicate the position d(=d(t of the car 20 n+2 ), d(t n+1 ), d(t n )) and the speed. Note that P in FIG. 9 n , t n respectively correspond to P in FIG. 8 n , t n in FIG. 8.

[0112] The magnitude of the difference between the speed v of the car 20 and the rated speed V RS increases in the order of t n , t n+1 , t n+2 , and exceeds the allowable range at t n+1 , t n+2 . Therefore, at t n+1 , t n+2 , the second deceleration determination unit 44b estimates that a speed abnormality has occurred.

[0113] The second deceleration determination unit 44b sequentially updates the target stop position in the order of t in accordance with the movement of the car 20 n , t n+1 , t n+2 .

[0114] At t n , since the magnitude of the difference between v and V RS is within the allowable range, the second deceleration determination unit 44b estimates that no speed abnormality has occurred. Therefore, as described above (FIG. 8), the second deceleration determination unit 44b sets the nearest position d0 (the position of the nearest floor) as the target stop position with d(t n ) as a reference. Accordingly, as described above (FIG. 8), the second deceleration determination unit 44b determines that there is no abnormality in the speed based on the deceleration characteristic represented by the deceleration curve 72.

[0115] At t n+1 , the second deceleration determination unit 44b estimates that the occurrence of the speed abnormality has started at time point t nd(t n Based on this, the nearest position, i.e., d0, is set as the target stopping position. Therefore, the second deceleration determination unit 44b sets the speed threshold V for determining the speed abnormality shown by the deceleration curve 72. th Based on this, determine whether there is an abnormality in speed v. n+1 In this case, as shown in Figure 9, v <V th Therefore, the second deceleration determination unit 44b determines that there is no abnormality in the speed v.

[0116] The second deceleration determination unit 44b stores the calculated difference values ​​in a time series and estimates the time when the abnormality started based on the stored difference values. In Embodiment 2, the second deceleration determination unit 44b, t n+1 When going back to a point in time earlier than [a certain point in time], the first time point t where the difference is zero is [a certain point in time]. n It is presumed that the abnormality began to occur at this point.

[0117] t n+2 In this case, the second deceleration determination unit 44b determines the time t when it is estimated that the occurrence of a speed abnormality has begun. n d(t n Based on this, the nearest position, i.e., d0, is set as the target stopping position. Therefore, the second deceleration determination unit 44b sets the speed threshold V for determining the speed abnormality shown by the deceleration curve 72. th Based on this, determine whether there is an abnormality in speed v. n+2 In this case, as shown in Figure 9, v≧V th Therefore, the second deceleration determination unit 44b determines that there is an abnormality in the speed v.

[0118] Figure 10 is a flowchart showing the speed abnormality detection operation of the safety control device 40 in Example 2.

[0119] When the safety control device 40 starts processing, in step 901, it uses the second deceleration determination unit 44b to determine whether the position d of the elevator car 20 is outside the range in which the first deceleration determination unit 44a determines an abnormality in the speed v of the elevator car 20 (hereinafter referred to as the "first deceleration determination range"). For example, the safety control device 40 determines whether the elevator car is located away from the end floors, that is, between the nearest floor to the lowest floor and the nearest floor to the highest floor. If the lowest floor and the highest floor are the 1st and 5th floors, respectively, the safety control device 40 determines whether the elevator car is located between the 2nd and 4th floors.

[0120] If the safety control device 40 determines that d is outside the first deceleration determination range (YES in step S901), it then executes step S902. If the safety control device 40 determines that d is not within the first deceleration determination range (NO in step S901), that is, if it determines that d is near an end floor, for example, between the terminal floor and the nearest floor to the terminal floor, it terminates the series of processes. After terminating the series of processes, the safety control device 40 uses the first deceleration determination unit 44a to determine whether or not there is an abnormality in speed v.

[0121] In step S902, the safety control device 40 uses the second deceleration determination unit 44b to determine the speed v and the rated speed V RS The difference Δv(=vV) RS Determine whether ) is outside the acceptable range. For example, the acceptable range is V RS It is set within a range of ±5% (-0.05V) RS ≤Δv ≤ 0.05V RS )

[0122] If the safety control device 40 determines that Δv is outside the acceptable range (YES in step S902), that is, if it estimates that an abnormality has occurred in v, it then executes step S903. If the safety control device 40 determines that Δv is not outside the acceptable range (NO in step S902), that is, if it estimates that no abnormality has occurred in v, it then executes step S904.

[0123] In step 903, the safety control device 40 uses the second deceleration determination unit 44b to set the nearest position d0 as the target stopping position, based on the position of the elevator car (d (start time of difference occurrence)) where the abnormality is estimated to have started. After executing step S903, the safety control device 40 then executes step S905.

[0124] In step 904, the safety control device 40 uses the second deceleration determination unit 44b to set the nearest position d0 as the target stopping position, based on the position of the elevator car (d (detected value)) where the speed v is currently detected. After executing step S904, the safety control device 40 then executes step S905.

[0125] In step 905, the safety control device 40 uses the second deceleration determination unit 44b to determine if the speed v of the elevator car is below the speed threshold V for speed abnormality determination. th Determine whether it is above or below. As mentioned above, V th This is equation (1) "V th =(2αL) 1 / 2 This is expressed as (α: deceleration, L: remaining distance to the target stopping position).

[0126] Note that L in (Equation 1) may be corrected by a predetermined value ΔL (constant: ΔL>0). In this case, Equation (1) becomes Equation (2) "V th =(2α(L-ΔL)) 1 / 2 This is changed to "[...]". As a result, the safety control device 40 can detect an abnormality in speed v at an early stage.

[0127] The safety control device 40 is configured such that v is V th If it is determined that the above is true (YES in step S905), that is, if it is determined that there is an abnormality in v, then step S906 is executed. Also, if v is V th Not more than (v <V th If it is determined that there is a problem (NO in step S905), that is, if it is determined that there is no abnormality in v, step S901 is executed again.

[0128] In step 906, the safety control device 40 uses the power cut-off unit 43 to cut off the power to the basket brake 33 by issuing a power cut-off command signal S C * The safety control device 40 terminates the series of processes after executing step S906.

[0129] As described above, according to Embodiment 2, an abnormality in the speed of the elevator car 20 is detected early near the terminal floor, and the elevator car 20 is decelerated and stopped with the terminal floor as the target stopping position. This makes it possible to reduce the speed at which the elevator car 20 enters the pit to almost zero. Therefore, the depth of the pit can be set to a depth where the lower part of the elevator car 20 does not come into contact with it, and the installation of a buffer can be omitted. Furthermore, if a buffer is provided, the stroke of the buffer can be shortened to reduce the depth of the pit.

[0130] Furthermore, according to Embodiment 2, even at a position far from the terminal floor, an abnormality in the speed of the elevator car 20 is detected early, and the elevator car 20 is decelerated and stopped at the nearest position as the target stopping position. As a result, the elevator car 20 can be brought to an emergency stop before it approaches the terminal floor. Therefore, the installation of buffers can be omitted.

[0131] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are described in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to delete some of the configurations of the embodiments, or to add or replace other configurations.

[0132] For example, instead of the absolute position detector 31, an image sensor may be installed on the elevator car 20, and the position of the elevator car 20 may be detected by the surface image of the guide rail acquired by the image sensor. Alternatively, a rotary encoder that rotates in accordance with the movement of the elevator car may be installed on the elevator car 20, and the position of the elevator car 20 may be detected based on the signal output by the rotary encoder.

[0133] Additionally, hoisting machines and elevator control devices may be installed in the machine room. [Explanation of Symbols]

[0134] 1 Elevator control device, 2 Electromagnetic contactor, 3 Motor, 4 Building power supply, 5 Hoisting machine brake, 20 Elevator car, 21 Main rope, 22 Counterweight, 23 Buffer, 24 Landing side door, 25 Elevator car side door, 26 Position detector, 27 Detected object, 31 Absolute position detector, 32 Detected object, 33 Car brake, 34 Emergency stop device, 40 Safety control device, 41 Position / speed detection unit, 42 Anomaly detection unit, 43 Power cut-off unit, 44 Terminal floor forced deceleration function unit, 50 Guide rail, 51 Contactor circuit, 52 Contact, 53 Contactor circuit, 54 Contact, 60 Movement detector, 101 Pulley for counterweight, 102 Direction change pulley, 103 Pulley for elevator car, 200 Hoistway, 300 Frame, 301 Magnetic core, 302 Coil, 303 Spring, 304 Suction body, 305 Guide part, 306 Brake shoe, 307 Support member, 308 Spring

Claims

1. In an elevator safety system that performs an emergency stop on an elevator car when an abnormality in the operating state of the elevator car, which is operated by an operation control system including an elevator control device, A braking device provided on the aforementioned elevator car, which grips the guide rail and brakes the elevator car, A position detector that detects information regarding the position of the elevator car in the hoistway, A safety control device that detects the position and speed of the elevator car in the elevator shaft based on the information detected by the position detector, and activates the brake device when it detects an abnormality in the operating state of the elevator car based on the detected position and speed, Equipped with, An elevator safety system characterized by being independent of the aforementioned operation control system.

2. In the elevator safety system described in claim 1, The safety control device is characterized by having a terminal floor forced deceleration function unit.

3. In the elevator safety system described in claim 2, The aforementioned terminal floor forced deceleration function unit is, An elevator safety system characterized by having a first deceleration determination unit that sets the terminal floor as the target stopping position and detects the abnormality near the terminal floor based on a first deceleration characteristic in which the elevator car decelerates toward the terminal floor by the braking device.

4. In the elevator safety system described in claim 3, The aforementioned terminal floor forced deceleration function unit further, An elevator safety system characterized by setting a target stopping position away from the terminal floor, and comprising a second deceleration determination unit that detects the abnormality at a position away from the terminal floor based on a second deceleration characteristic in which the elevator car decelerates toward the target stopping position by the braking device.

5. In the elevator safety system described in claim 4, The second deceleration determination unit is, To estimate whether or not the aforementioned abnormality has occurred, An elevator safety system characterized in that, when it is estimated that the aforementioned abnormality has occurred, the nearest position where the elevator can be decelerated and stopped by the braking device is set as the target stopping position, based on the position of the elevator car where it is estimated that the occurrence of the aforementioned abnormality began.

6. In the elevator safety system described in claim 5, The second deceleration determination unit is, An elevator safety system characterized in that, if it is presumed that the aforementioned abnormality has not occurred, the nearest position is set to the target stopping position based on the position of the elevator car to be detected.

7. In the elevator safety system according to claim 5 or claim 6, The elevator safety system is characterized in that the second deceleration determination unit estimates whether or not the abnormality has occurred based on the difference between the speed of the elevator car and the rated speed.

8. In the elevator safety system according to claim 5 or claim 6, An elevator safety system characterized in that the nearest location is the nearest floor.

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