Safety device for an elevator

Abstract

A safety device of an elevator capable of suppressing a decrease in availability of the elevator. A host node (63) monitors whether a traveling speed of a car (42) reaches an excessive speed level based on a signal from an upper reference position switch (45), a signal from a lower reference position switch (46), and information related to a traveling direction of the car (42). As the excessive speed level, a first speed level and a second speed level are set to the host node (63). The second speed level is a lower level than the first speed level. The host node (63) applies the second speed level to upward traveling of the car (42) in a case where an upper communication failure is detected, and applies the second speed level to downward traveling of the car (42) in a case where a lower communication failure is detected.

Description

Technical Field

[0001] This invention relates to safety devices for elevators. Background Technology

[0002] In conventional elevator systems, an excessive speed level for the car is set, corresponding to the distance between the car and the terminal floor. When the car exceeds this excessive speed level, a forced deceleration device at the terminal floor forces the car to slow down and stop (e.g., Patent Document 1). Furthermore, in conventional elevator safety systems, signals from the terminal floor switch within the hoistway are transmitted to the controller via a safety bus. When a communication malfunction occurs on the safety bus, the elevator may sometimes stop (e.g., Patent Document 2).

[0003] Patent Document 1: Japanese Patent No. 4668186

[0004] Patent Document 2: Japanese Patent No. 4601827

[0005] For example, in conventional elevator systems where a safety bus, similar to those in conventional elevator safety systems, is used to save on system wiring, proper monitoring of the forced deceleration device based on the terminal floor cannot be performed when a communication failure occurs on the safety bus. Therefore, it is necessary to forcibly decelerate and stop the car, potentially reducing elevator availability. Summary of the Invention

[0006] The present invention was made to solve the above-mentioned problems, and its purpose is to provide an elevator safety device that can suppress the reduction of elevator availability.

[0007] The elevator safety device of the present invention comprises: an upper switch node, which receives a signal from an upper reference position switch disposed in the hoistway; a lower switch node, which receives a signal from a lower reference position switch disposed in the hoistway below the upper reference position switch; a main node, which performs monitoring processing based on the signals from the upper reference position switch, the signals from the lower reference position switch, and information related to the car's travel direction, the monitoring processing being the monitoring of whether the car's travel speed has reached an excessive speed level; and a communication line connecting the upper switch node and the lower reference position switch. The switch node is connected to the main node. As an excessive speed level, the main node is set with a first speed level and a second speed level lower than the first speed level. The main node monitors the presence or absence of upper communication faults, which are communication faults between the main node and the upper switch node, and lower communication faults, which are communication faults between the main node and the lower switch node. When the main node detects an upper communication fault, it applies the second speed level to monitor the upward movement of the car. When the main node detects a lower communication fault, it applies the second speed level to monitor the downward movement of the car.

[0008] Invention Effects

[0009] The elevator safety device according to the present invention can suppress the reduction of elevator availability. Attached Figure Description

[0010] Figure 1 This is a schematic structural diagram of the elevator device of Embodiment 1, represented by a partial box.

[0011] Figure 2 This is a block diagram representing the structure of communication packets between upper and lower switch nodes.

[0012] Figure 3 This diagram shows the elevator's operating status when the first speed level is applied to both the upward and downward travel of the car.

[0013] Figure 4 This is a diagram showing the elevator's operating status when an upper communication failure is detected.

[0014] Figure 5 This is a diagram showing the elevator's operating status when a communication failure is detected in the lower section.

[0015] Figure 6 It is used for explanation Figure 1 An activity diagram illustrating the processing flow executed by the safety device.

[0016] Figure 7 It is used for explanation Figure 1An activity diagram of the processing flow executed by the upper or lower switch node.

[0017] Figure 8 It is used for explanation Figure 1 The activity diagram of the processing flow executed by the master node.

[0018] Figure 9 It means Figure 1 The activity diagram details the excessive speed level calculations performed by the master node.

[0019] Figure 10 This diagram shows the elevator's operating status when the second speed level is applied to both the upward and downward travel of the car.

[0020] Figure 11 This is a structural diagram of the first example of a processing circuit that implements the function of the safety device of the elevator in Embodiment 1.

[0021] Figure 12 This is a structural diagram of a second example of a processing circuit that implements the function of the safety device of the elevator in Embodiment 1.

[0022] Label Explanation

[0023] 4a: Hoistway; 42: Car; 45: Upper reference position switch; 46: Lower reference position switch; 48: Car buffer; 49: Counterweight buffer; 60: Safety device; 61: Upper switch node; 62: Lower switch node; 63: Main node; 64: Communication line. Detailed Implementation

[0024] The embodiments are described below with reference to the accompanying drawings.

[0025] Implementation Method 1

[0026] Figure 1 This is a schematic structural diagram of the elevator device according to Embodiment 1, represented by a partial box. The elevator device includes an AC power supply 10, a traction machine drive device 20, a traction machine 30, hoistway equipment 40, an operation management device 50, and a safety device 60.

[0027] AC power supply 10 generates AC voltage.

[0028] The traction machine drive unit 20 has MC contact 21, first rectifier 22, inverter 23, second rectifier 24, DC / DC converter 25, brake drive circuit 26 and BK contact 27.

[0029] AC voltage from AC power supply 10 is input to MC contact 21 and the second rectifier 24. MC contact 21 is the main contact of contactor MC. MC contact 21 is located between AC power supply 10 and the first rectifier 22. The first rectifier 22 rectifies the AC voltage from AC power supply 10 into DC voltage and outputs the rectified DC voltage to inverter 23. Inverter 23 converts the DC voltage output from the first rectifier 22 into AC voltage and outputs it to traction machine 30.

[0030] The second rectifier 24 rectifies the AC voltage from the AC power supply 10 into a DC voltage and outputs the rectified DC voltage to the DC / DC converter 25. The DC / DC converter 25 converts the voltage level of the DC voltage rectified by the second rectifier 24 into the operating voltage level of the brake drive circuit 26. The brake drive circuit 26 outputs a signal to the traction machine 30 to brake the traction machine 30. The BK contact 27 connects or disconnects the brake drive circuit 26 from the traction machine 30.

[0031] The traction machine 30 has a drive pulley 31, a motor 32 and a brake 33.

[0032] The hoistway equipment 40 includes a suspension body 41, a car 42, a counterweight 43, a switch cam 44, an upper reference position switch 45, a lower reference position switch 46, a speed encoder 47, a car buffer 48, and a counterweight buffer 49.

[0033] The suspension body 41 is wound around the drive sheave 31. Multiple ropes or belts are used as the suspension body 41. A car 42 is connected to the first end of the suspension body 41. A counterweight 43 is connected to the second end of the suspension body 41. The car 42 and counterweight 43 are suspended within the hoistway 4a by the suspension body 41 and move up and down within the hoistway 4a by rotating the drive sheave 31.

[0034] The upper reference position switch 45 is located at the upper reference position within the shaft 4a. The lower reference position switch 46 is located at the lower reference position within the shaft 4a. The lower reference position is located below the upper reference position.

[0035] The upper reference position switch 45 has a first switch 45a and a second switch 45b. The first switch 45a is located at a first reference position in the highest floor section within the hoistway 4a. The second switch 45b is located at a second reference position below the first reference position.

[0036] The lower reference position switch 46 has a third switch 46a and a fourth switch 46b. The third switch 46a is located at the third reference position in the lowest floor section within the shaft 4a. The fourth switch 46b is located at the fourth reference position, which is above the third reference position.

[0037] When the car 42 rises from below and reaches the second reference position, the switch cam 44 contacts the second switch 45b. This changes the state of the second switch 45b from the ON state to the OFF state. When the car 42 rises further and reaches the first reference position, the switch cam 44 contacts the first switch 45a. This changes the state of the first switch 45a from the ON state to the OFF state.

[0038] When the car 42 descends from above and reaches the fourth reference position, the switch cam 44 contacts the fourth switch 46b. As a result, the state of the fourth switch 46b changes from the ON state to the OFF state. When the car 42 descends further and reaches the third reference position, the switch cam 44 contacts the third switch 46a. As a result, the state of the third switch 46a changes from the ON state to the OFF state.

[0039] The speed encoder 47 detects the travel speed and travel direction of the car 42.

[0040] A car buffer 48 and a counterweight buffer 49 are provided at the bottom of the hoistway 4a. The car buffer 48 is located directly below the car 42. The counterweight buffer 49 is located directly below the counterweight 43. Furthermore, hydraulic buffers are used for both the car buffer 48 and the counterweight buffer 49. In this embodiment, the car buffer 48 and the counterweight buffer 49 have the same performance characteristics.

[0041] The car buffer 48 and the counterweight buffer 49 are each set with an allowable collision speed.

[0042] The operation management device 50 includes an operation management unit 51, an MC coil 52, a BK coil 53, an SF contact 54, a first semiconductor switch 55, and a second semiconductor switch 56. The MC coil 52 is the coil of the contactor MC. The BK coil 53 is the coil of the brake relay BK. The SF contact 54 is the main contact of the safety relay SF.

[0043] The operation management unit 51 manages the operation of the car 42. Specifically, the operation management unit 51 generates a motor drive signal and outputs the generated motor drive signal to the inverter 23. The operation management unit 51 generates a brake drive signal and outputs the generated brake drive signal to the brake drive circuit 26.

[0044] The operation management unit 51 generates a control signal for controlling the contactor MC and supplies the generated control signal to the first semiconductor switch 55.

[0045] When the first semiconductor switch 55 is turned on, current flows through the MC coil 52, and therefore, the MC contact 21 is closed. Thus, power is supplied to the motor 32 in this state. Conversely, when the first semiconductor switch 55 is turned off, no current flows through the MC coil 52, and therefore, the MC contact 21 is open. Thus, the power supply to the motor 32 is cut off in this state.

[0046] The operation management unit 51 generates a control signal for controlling the brake relay BK and supplies the generated control signal to the second semiconductor switch 56.

[0047] When the second semiconductor switch 56 is turned on, current flows through the BK coil 53, and therefore, the BK contact 27 is closed. Thus, in this case, power is supplied to the brake 33. Conversely, when the second semiconductor switch 56 is turned off, no current flows through the BK coil 53, and therefore, the BK contact 27 is open. Thus, in this case, the power supply to the brake 33 is cut off.

[0048] Thus, the operation management device 50 cuts off the power supply to the motor 32 and the brake 33 as needed. When the power supply is cut off, the motor 32 loses its driving force on the drive pulley 31. When the power supply is cut off, the brake 33 generates a braking force on the drive pulley 31.

[0049] Safety device 60 includes an upper switch node 61, a lower switch node 62, a main node 63, a communication line 64, an SF coil 65, and a third semiconductor switch 66. The SF coil 65 is the coil of the safety relay SF.

[0050] The upper switch node 61 receives signals from the upper reference position switch 45. That is, the upper switch node 61 receives signals from the first switch 45a and from the second switch 45b. The upper switch node 61 is connected to the communication line 64.

[0051] The lower switch node 62 receives signals from the lower reference position switch 46. That is, the lower switch node 62 receives signals from the third switch 46a and the fourth switch 46b. The lower switch node 62 is connected to the communication line 64.

[0052] The master node 63 is a processing device that performs monitoring processing. Monitoring processing involves monitoring whether the travel speed of the car 42 has reached an excessive speed level, based on signals from the upper reference position switch 45, signals from the lower reference position switch 46, and information related to the speed and direction of travel of the car 42. Information related to the speed and direction of travel of the car 42 is sent from the speed encoder 47 to the master node 63.

[0053] Communication line 64 is a bus-type communication line. The master node 63 and the upper switch node 61 can send and receive packets to each other via communication line 64 using a serial communication protocol. Similarly, the master node 63 and the lower switch node 62 can send and receive packets to each other via communication line 64 using a serial communication protocol.

[0054] As a result of the monitoring process, the master node 63 generates a control signal for controlling the safety relay SF and provides the generated control signal to the third semiconductor switch 66.

[0055] When the third semiconductor switch 66 is closed, current flows through the SF coil 65, therefore, the SF contact 54 is closed. Thus, in this case, power is supplied to the MC coil 52 and the BK coil 53. Conversely, when the third semiconductor switch 66 is open, no current flows through the SF coil 65, therefore, the SF contact 54 is open. Thus, in this case, the power supply to the MC coil 52 and the BK coil 53 is cut off.

[0056] The main node 63 is set with an excessive speed level for the car 42. When the car 42's travel speed exceeds the excessive speed level, the main node 63 disconnects the third semiconductor switch 66, thereby disconnecting the safety relay SF. This stops the power supply to the motor 32 and the brake 33, bringing the car 42 to an emergency stop.

[0057] As a speed level, the master node 63 is assigned a first speed level and a second speed level. The second speed level is lower than the first speed level.

[0058] Master node 63 monitors for both upstream and downstream communication failures. An upstream communication failure refers to a communication failure between master node 63 and upstream switch node 61. A downstream communication failure refers to a communication failure between master node 63 and downstream switch node 62.

[0059] If no upper communication failure is detected, the master node 63 maintains monitoring and processing of the car 42 traveling upwards at the first speed level. If no lower communication failure is detected, the master node 63 maintains monitoring and processing of the car 42 traveling downwards at the first speed level.

[0060] Figure 2 This is a block diagram illustrating the structure of communication packets between the upper and lower switching nodes. Upper switching node communication packet 71 is... Figure 1 The communication packets sent by the upper switch node 61. The communication packets 72 of the lower switch node are... Figure 1 The communication packets sent by the lower switch node 62.

[0061] The upper switch node communication packet 71 includes a packet identification header 73, upper reference position switch information 74, a timestamp 76, and error correction information 77. The lower switch node communication packet 72 includes a packet identification header 73, lower reference position switch information 75, a timestamp 76, and error correction information 77.

[0062] The packet identification header 73 is used by the receiving node to determine whether the received packet is a legitimate packet. The timestamp 76 is used to determine whether the packet was sent at a predetermined time and within a predetermined period. The error correction information 77 is used to check the integrity of the communication packet data.

[0063] Next, the monitoring process of master node 63 will be explained in more detail. Figure 3 This diagram illustrates the elevator's operating status when the first speed level is applied to both the upward and downward travel of the car 42. That is, in... Figure 3 In the example, neither the upstream communication failure nor the downstream communication failure was detected. Figure 3 The diagram shows the scenario where the car 42 does not stop at any intermediate floor but travels back and forth between the highest and lowest floors. Hereinafter, regarding the travel speed of the car 42, the upward travel of the car 42 will be described with "up" as the positive direction, and the downward travel of the car 42 will be described with "down" as the positive direction.

[0064] The upward speed 81 of the car 42 is zero at the lowest floor position, increases as the car 42 rises, and reaches its maximum upward speed. Then, near the highest floor position, the upward speed 81 decelerates, and at the highest floor position, the upward speed 81 is zero. The downward speed 83 of the car 42 is similar to the upward speed 81, and is at its maximum downward speed except near the highest and lowest floor positions.

[0065] If the master node 63 is capable of monitoring the maximum speed and detects neither an upper nor lower communication failure, the master node 63 will maintain both the upward excessive speed level 82 and the downward excessive speed level 84 at speed level 1. The upward excessive speed level 82 is the excessive speed level for the car 42 while it is moving upwards. The downward excessive speed level 84 is the excessive speed level for the car 42 while it is moving downwards.

[0066] The first upward speed level is set such that the car 42 can travel at a speed below the maximum upward speed. The first upward speed level is given by the following formula (1).

[0067] V_os_up(X)=[2×d×(P_top-x+P_mrg)] 1 / 2 +V_mrg···(1)

[0068] Here, V_os_up(X) is the excessive upward speed level, d is the standard deceleration, P_top is the highest floor position, x is the current position of car 42, P_mrg is the position margin, and V_mrg is the speed margin. The highest floor position P_top is the position corresponding to the first reference position.

[0069] Furthermore, the maximum upward speed is set to a speed higher than the permissible collision speed of the counterweight buffer 49. Additionally, the first speed level is set to be below the permissible collision speed of the counterweight buffer 49 at the highest floor position P_top.

[0070] The first downward speed level is set so that the car 42 can travel at a speed below the maximum downward speed. The first downward speed level is given by the following formula (2).

[0071] V_os_dn(X)=[2×d×(x-P_bot+P_mrg)] 1 / 2 +V_mrg···(2)

[0072] Here, V_os_dn(X) is the downward excessive velocity level, and P_bot is the lowest floor position. The lowest floor position P_bot is the position corresponding to the third reference position.

[0073] Furthermore, the maximum downward speed is set to a speed higher than the permissible collision speed of the car buffer 48. Additionally, the first speed level is set to be below the permissible collision speed of the car buffer 48 at the lowest floor position P_bot.

[0074] Therefore, under normal elevator conditions, the car 42 can travel at the maximum upward speed and the maximum downward speed within the range of the maximum upward speed level 82 and the maximum downward speed level 84.

[0075] On the other hand, if the elevator device malfunctions and the car 42 travels at a speed exceeding the upward excessive speed level 82 or the downward excessive speed level 84, the main node 63 disconnects the safety relay SF, thereby stopping the power supply to the motor 32 and the brake 33.

[0076] Next, we will explain the monitoring and handling procedures in the event of an upper-level communication failure. Figure 4 This is a diagram showing the elevator's operating status when a communication failure is detected above. Figure 4 In, with Figure 3Similarly, it shows a scenario where the car 42 does not stop at an intermediate floor but instead travels back and forth between the highest and lowest floors. Furthermore, in Figure 4 In the example shown, no lower-level communication failure was detected.

[0077] In the event of an upper communication failure, the master node 63 applies a second speed level to monitor the upward movement of the car 42. The second speed level is lower than the maximum upward speed and is set to a constant value below the permissible collision speed of the counterweight buffer 49.

[0078] In this case, master node 63 instructs operation management unit 51 to set the maximum upward travel speed of car 42 below the upward speed limit, so that car 42 does not exceed the excessive upward speed level 86, i.e., the second speed level. The upward speed limit is a speed lower than the second speed level and lower than the permissible collision speed of counterweight buffer 49. Master node 63 instructs operation management unit 51 to set the maximum upward travel speed of car 42 below the upward speed limit.

[0079] Therefore, the upward travel speed 85 during a malfunction is zero at the lowest floor position, increases as the car 42 rises, and reaches the upward speed limit. The upward travel speed 85 during a malfunction is the upward travel speed of the car 42 in the event of an upper communication malfunction. Then, near the highest floor position, the upward travel speed 85 during a malfunction decelerates, and at the highest floor position, the upward travel speed 85 during a malfunction is zero.

[0080] exist Figure 4 In the example shown, no lower communication failure was detected; therefore, the master node 63 maintained monitoring of the downward movement of the car 42 at the first speed level. Thus, the car 42 was able to travel at the maximum downward speed.

[0081] Next, we will explain the monitoring and handling procedures in the event of a detected lower-level communication failure. Figure 5 This is a diagram showing the elevator's operating status when a communication failure is detected in the lower section. Figure 5 In, with Figure 3 Similarly, it shows a scenario where the car 42 does not stop at an intermediate floor but instead travels back and forth between the highest and lowest floors. Furthermore, in Figure 5 In the example shown, no upper-level communication failure was detected.

[0082] In the event of a lower communication failure, the master node 63 applies a second speed level to monitor the downward movement of the car 42. The second speed level is a level lower than the maximum downward speed and is set to a constant value below the permissible collision speed of the car buffer 48.

[0083] In this case, master node 63 instructs operation management unit 51 to set the maximum downward travel speed of car 42 below the downward limit speed, so that car 42 does not exceed the excessive downward speed level 88, i.e., the second speed level. The downward limit speed is a speed lower than the second speed level and lower than the permissible collision speed of car buffer 48. Master node 63 instructs operation management unit 51 to set the maximum downward travel speed of car 42 below the downward limit speed.

[0084] Therefore, the downward travel speed 87 during a malfunction is zero at the highest floor position, increases as the car 42 descends, and reaches the downward speed limit. The downward travel speed 87 during a malfunction is the downward travel speed of the car 42 in the event of a lower communication malfunction. Then, near the lowest floor position, the downward travel speed 87 during a malfunction decelerates, and at the lowest floor position, the downward travel speed 87 during a malfunction is zero.

[0085] exist Figure 5 In the example shown, no upper communication failure was detected; therefore, the master node 63 maintained monitoring of the car 42's upward movement at the first speed level. Thus, the car 42 was able to travel at its maximum upward speed.

[0086] Next, the processing procedure performed by safety device 60 will be explained in more detail. Figure 6 It is used for explanation Figure 1 The activity diagram shows the processing flow executed by safety device 60. At node N101, when the power to safety device 60 is turned on, the processing of safety device 60 begins.

[0087] At node N102, the upper switch node 61 performs upper switch node processing based on the signal from the upper reference position switch 45 and sends the upper switch node communication packet 71 to node N104.

[0088] The lower switch node 62, located at node N103, performs lower switch node processing based on the signal from the lower reference position switch 46, and sends the lower switch node communication packet 72 to node N104.

[0089] At node N104, master node 63 executes master node processing based on the upper switch node communication group 71, the lower switch node communication group 72, and the signal from the speed encoder 47, and outputs a safety relay disconnection command. At node N105, when the power supply to safety device 60 is disconnected, at node N106, all processing performed by safety device 60 ends.

[0090] Figure 7 It is used for explanation Figure 1The activity diagram shows the processing flow executed by the upper switch node 61. At node N201, when the power to the safety device 60 is turned on, the processing of the upper switch node 61 begins. Figure 7 The processing is repeated in each constant control cycle of node N202.

[0091] At node N203, the upper switch node 61 performs switch state detection processing based on the signal from the upper reference position switch 45, generating information about the upper reference position switch state. This information pertains to the on / off state of each switch in the first switch 45a and the second switch 45b.

[0092] Next, at node N204, the upper switch node 61 performs inter-node communication processing based on the upper reference position switch state information, generating an upper switch node communication packet 71. That is, the inter-node communication processing is the process of encoding the generated upper reference position switch state into a switch node communication packet.

[0093] Next, the upper switch node 61 temporarily terminates this process at node N205.

[0094] Processing of lower switch node 62 and Figure 7 The processing is the same, therefore its description is omitted. Furthermore, in the processing of the lower switch node 62, Figure 7 The “upper reference position” shown has been replaced with the “lower reference position”, and the “upper switch node” has been replaced with the “lower switch node”.

[0095] Figure 8 It is used for explanation Figure 1 The activity diagram shows the processing flow executed by the master node 63. At node N301, when the power to the safety device 60 is turned on, the processing of the master node 63 begins. Figure 8 The processing is repeated in each constant control cycle of node N302.

[0096] At node N303, master node 63 performs inter-node communication processing based on upper switch node communication packet 71 and lower switch node communication packet 72. Master node 63 generates reference position switch state information by performing inter-node communication processing. That is, master node 63 decodes upper switch node communication packet 71 and lower switch node communication packet 72 to generate reference position switch state information. The reference position switch state information pertains to the on / off state of each of the following switches: 1st switch 45a, 2nd switch 45b, 3rd switch 46a, and 4th switch 46b.

[0097] In addition, at node N303, the master node 63 generates communication fault information based on the packet identification headers 73, timestamps 76, and error correction information 77 of the upper switch node communication packet 71 and the lower switch node communication packet 72.

[0098] Next, at node N304, the master node 63 inputs the status of the reference position switch based on the information of the reference position switch status.

[0099] Next, the master node 63 determines at node N305 whether there is a "switch detection". A switch detection means that the state of each switch of the upper reference position switch 45 and the state of each switch of the lower reference position switch 46 changes from the on state to the off state.

[0100] When a "switch is detected", the master node 63 sets the switch position to "car position" at node N306.

[0101] Next, the master node 63 calculates the car movement at node N307 based on the signal from the speed encoder 47. The calculated car movement is then added to the car position set at node 306.

[0102] In addition, the master node 63 calculates the car speed at node N308 based on the signal from the speed encoder 47.

[0103] Next, at node N309, master node 63 calculates the excessive upward speed level and the excessive downward speed level based on the car position and communication fault information.

[0104] Next, at node N310, master node 63 detects whether the travel speed of car 42 exceeds the excessive speed limit based on the car speed, the excessive speed level for upward travel, and the excessive speed level for downward travel. When master node 63 detects that the travel speed of car 42 exceeds the excessive speed limit, it generates information about the excessive speed detection status of the car.

[0105] Next, at node N311, master node 63 performs safety output processing based on the information indicating that the car is traveling too fast, generating a safety relay cut-off command. Then, master node 63 temporarily terminates this process at node N312.

[0106] On the other hand, if there is no "switch detection" at node N305, the master node 63 does not set the car position to the switch position, but calculates the car movement at node N307 and the car speed at node N308.

[0107] Figure 9 It means Figure 1The activity diagram details the excessive speed level calculations performed by the master node 63. At node N401, processing by the master node 63 begins when the power to the safety device 60 is turned on.

[0108] Master node 63 determines at node N402 whether maximum speed monitoring is possible. Being in a state where maximum speed monitoring is possible means that the elevator system is functioning normally and the first speed level can be used as the excessive speed level. If maximum speed monitoring is possible, master node 63 at node N403 detects the communication fault status of the upper switch node based on communication fault information.

[0109] Next, the master node 63 determines at node N404 whether a communication failure has occurred at the upper switch node 61. If no communication failure has occurred, i.e., communication is normal, the master node 63 at node N405 maintains the monitoring process of applying the first speed level as the excessive upward speed level based on the car position information.

[0110] Next, the master node 63 determines at node N406 whether maximum speed monitoring is possible. If maximum speed monitoring is possible, the master node 63 detects the communication fault status of the lower switch node at node N407 based on the communication fault information.

[0111] Next, the master node 63 determines at node N408 whether a communication failure has occurred at the lower switch node 62. If no communication failure has occurred, i.e., communication is normal, the master node 63 at node N409 maintains the monitoring process of applying the first speed level as the downward excessive speed level based on the car position information.

[0112] Next, master node 63 temporarily terminates this process at node N410.

[0113] On the other hand, if it is determined that maximum speed monitoring cannot be performed at node N402, the master node 63 applies the second speed level as an upward excessive speed level at node N411. Additionally, if it is determined that maximum speed monitoring cannot be performed at node N406, the master node 63 applies the second speed level as a downward excessive speed level at node N412.

[0114] Furthermore, if a communication failure is detected at node N404 for the upper switch node 61, the master node 63 applies the second speed level at node N411 as an excessive upward speed level. Similarly, if a communication failure is detected at node N408 for the lower switch node 62, the master node 63 applies the second speed level at node N412 as an excessive downward speed level.

[0115] Thus, the safety device 60 of the elevator in Embodiment 1 includes an upper switch node 61, a lower switch node 62, a main node 63, and a communication line 64. The upper switch node 61 receives a signal from an upper reference position switch 45. The upper reference position switch 45 is located within the hoistway 4a. The lower switch node 62 receives a signal from a lower reference position switch 46. The lower reference position switch 46 is located within the hoistway 4a below the upper reference position switch 45.

[0116] The master node 63 performs monitoring processing. This monitoring processing involves checking whether the travel speed of the car 42 has reached an excessive speed level, based on signals from the upper reference position switch 45, signals from the lower reference position switch 46, and information related to the travel direction of the car 42. Communication line 64 connects the upper switch node 61 and the lower switch node 62 to the master node 63.

[0117] As a speed level, the master node 63 is assigned a first speed level and a second speed level. The second speed level is lower than the first speed level.

[0118] Master node 63 monitors for both upstream and downstream communication failures. An upstream communication failure refers to a communication failure between master node 63 and upstream switch node 61. A downstream communication failure refers to a communication failure between master node 63 and downstream switch node 62.

[0119] If the master node 63 detects an upper communication failure, it applies a second speed level to monitor the upward movement of the car 42. If the master node 63 detects a lower communication failure, it applies a second speed level to monitor the downward movement of the car 42.

[0120] Therefore, even if an upper or lower communication failure is detected, the elevator will not stop immediately but will continue to be monitored and processed. This helps to prevent a decrease in elevator availability.

[0121] In addition, if no upper communication failure is detected, the master node 63 maintains monitoring and processing of the car 42 traveling upwards at the first speed level. If no lower communication failure is detected, the master node 63 maintains monitoring and processing of the car 42 traveling downwards at the first speed level.

[0122] Therefore, for travel from the reference position switch corresponding to the switch node where a communication failure has occurred towards the reference position switch corresponding to the switch node where no communication failure has been detected, monitoring processing at the first speed level is maintained. This further suppresses the reduction in elevator availability.

[0123] In addition, the master node 63 instructs the operation management unit 51 to set the highest driving speed during the period when monitoring is performed using the second speed level to a value lower than the second speed level.

[0124] Therefore, during the monitoring process of applying the second speed level, it is possible to prevent the elevator from having to stop urgently due to the car 42 exceeding the second speed level. This further reduces the likelihood of elevator availability degradation.

[0125] In addition, the second speed level is set below the permissible collision speed of the car buffer 48 and the counterweight buffer 49. The car buffer 48 and the counterweight buffer 49 are located at the bottom of the hoistway 4a.

[0126] Therefore, even if monitoring is performed at the second speed level, the possibility of the car 42 colliding with the buffer due to exceeding the permissible collision speed can be reduced, even if a situation arises that requires the elevator to stop urgently.

[0127] Furthermore, in Embodiment 1, if an upper communication failure is detected, the second speed level is applied only to the upward travel of the car 42, and if a lower communication failure is detected, the second speed level is applied only to the downward travel of the car 42. However, the master node 63 may also apply the second speed level to both the upward and downward travel of the car 42 if either an upper or lower communication failure is detected.

[0128] Figure 10 This diagram illustrates the elevator's operating status when the second speed level is applied to both the upward and downward travel of the car 42. Figure 10 In the example, at least one of the upper communication failure and the lower communication failure was detected.

[0129] In this case, the master node 63 sets the maximum upward travel speed of the car 42 below the upward speed limit to ensure that the car 42 does not exceed the second speed level. Furthermore, the master node 63 sets the maximum downward travel speed of the car 42 below the downward speed limit to ensure that the car 42 does not exceed the second speed level.

[0130] Furthermore, the first speed level is not limited to the levels represented by equations (1) and (2). For upward travel of the car 42, the first speed level is set below the permissible collision speed of the counterweight buffer 49 at the highest floor position, and is set above the maximum upward speed at intermediate floors. For downward travel of the car 42, the first speed level is set below the permissible collision speed of the car buffer 48 at the lowest floor position, and is set above the maximum downward speed at intermediate floors.

[0131] Furthermore, the first speed level for upward travel of the car 42 and the first speed level for downward travel of the car 42 do not necessarily have to be symmetrical. Similarly, the second speed level for upward travel of the car 42 and the second speed level for downward travel of the car 42 do not necessarily have to be symmetrical. For example, the permissible collision speed of the car buffer 48 and the permissible collision speed of the counterweight buffer 49 may be different.

[0132] In addition, the upper reference position switch 45 and the lower reference position switch 46 each have two reference position switches, but it is sufficient for each to have at least one switch.

[0133] Furthermore, if the upper reference position switch 45 has multiple switches, the upper switch node 61 can simply aggregate the signals input from the multiple switches. Similarly, if the lower reference position switch 46 has multiple switches, the lower switch node 62 can simply aggregate the signals input from the multiple switches.

[0134] Additionally, the lowest floor position P_bot corresponds to the third reference position, but the lowest floor position P_bot does not necessarily need to correspond to the third reference position. The lowest floor position P_bot and the third reference position can also be set independently in the terminal area below shaft 4a.

[0135] Furthermore, the communication between the master node 63 and the upper switch node 61, as well as the communication between the master node 63 and the lower switch node 62, is not limited to serial communication.

[0136] In addition, communication line 64 is not limited to bus-type communication lines.

[0137] Furthermore, the structure of communication packets is not particularly limited to Figure 2 The example shown.

[0138] Furthermore, the structures of the AC power supply 10, the traction machine drive unit 20, and the traction machine 30 are not limited to the following: Figure 1 The structure shown.

[0139] Alternatively, spring buffers or buffers can be used for car buffer 48 and counterweight buffer 49.

[0140] Furthermore, the location of the car buffer 48 and the counterweight buffer 49 is not limited to the bottom of the hoistway 4a, but can also be the upper part of the hoistway 4a, the car 42, or the counterweight 43.

[0141] In addition, the type of elevator is not limited to Figure 1 The type shown could also be, for example, a 2:1 rope-winding elevator.

[0142] In addition, the function of the safety device 60 of the elevator in Embodiment 1 is realized by the processing circuit. Figure 11 This is a structural diagram of a first example of a processing circuit that implements the function of the safety device 60 of the elevator in Embodiment 1. The processing circuit 100 in the first example is dedicated hardware.

[0143] Furthermore, the processing circuit 100 may be equivalent to a single circuit, a composite circuit, a programmable processor, a parallel programmable processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof.

[0144] in addition, Figure 12 This is a structural diagram of a second example of a processing circuit that implements the function of the elevator safety device 60 in Embodiment 1. The processing circuit 200 of the second example includes a processor 201 and a memory 202.

[0145] In the processing circuit 200, the function of the elevator safety device 60 is implemented through software, firmware, or a combination of software and firmware. The software and firmware are described as programs and stored in the memory 202. The processor 201 implements the function by reading and executing the programs stored in the memory 202.

[0146] The program stored in memory 202 can also be described as a program that causes the computer to execute the steps or methods described above. Here, memory 202 is, for example, a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory). Additionally, disks, floppy disks, optical disks, compact discs, mini-disks, and DVDs also correspond to memory 202.

[0147] In addition, the functions of the elevator safety device 60 mentioned above can be partially implemented using dedicated hardware and partially implemented using software or firmware.

[0148] In this way, the processing circuit can implement the functions of the elevator safety device 60 described above through hardware, software, firmware, or a combination thereof.

[0149] The preferred embodiments have been described in detail above, but are not limited to the embodiments described above. Various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0150] The various aspects of the present invention are summarized and described below as an appendix.

[0151] (Postscript 1)

[0152] A safety device for an elevator, wherein the safety device comprises:

[0153] The upper switch node is input with a signal from the upper reference position switch located inside the shaft.

[0154] The lower switch node is input with a signal from the lower reference position switch, which is located in the shaft below the upper reference position switch.

[0155] The master node performs monitoring processing based on signals from the upper reference position switch, signals from the lower reference position switch, and information related to the car's travel direction. This monitoring processing involves checking whether the car's travel speed has reached an excessive speed level; and

[0156] A communication line connects the upper and lower switch nodes to the main node.

[0157] As for the excessive speed level, the master node is set with a first speed level and a second speed level lower than the first speed level.

[0158] The master node monitors the presence or absence of upper communication faults, which are communication faults between the master node and the upper switch node, and the presence or absence of lower communication faults, which are communication faults between the master node and the lower switch node.

[0159] In the event of an upper communication failure, the master node applies the second speed level to perform the monitoring process for the upward movement of the car.

[0160] In the event of a lower communication failure, the master node applies the second speed level to perform the monitoring process for the downward movement of the car.

[0161] (Postscript 2)

[0162] In the elevator safety devices described in Appendix 1

[0163] If the upper communication failure is not detected, the master node continues to apply the first speed level of monitoring to the upward movement of the car.

[0164] In the absence of detecting the lower communication failure, the master node maintains the monitoring process of the car moving downwards at the first speed level.

[0165] (Note 3)

[0166] In the elevator safety devices described in Appendix 1 or Appendix 2

[0167] The master node instructs the operation management department, which manages the operation of the car, to set the highest value of the travel speed during the period when the monitoring process is performed using the second speed level to a value lower than the second speed level.

[0168] (Note 4)

[0169] In any of the elevator safety devices described in Appendix 1 to Appendix 3

[0170] The second speed level is set below the permissible collision speed of the buffer located at the bottom of the shaft.

Claims

1. A safety device for an elevator, wherein, The elevator's safety devices include: The upper switch node is input with a signal from the upper reference position switch located inside the shaft. The lower switch node is input with a signal from the lower reference position switch, which is located in the shaft below the upper reference position switch. The master node performs monitoring processing based on signals from the upper reference position switch, signals from the lower reference position switch, and information related to the car's travel direction. This monitoring processing monitors whether the car's travel speed has reached an excessive speed level. as well as A communication line connects the upper and lower switch nodes to the main node. As for the excessive speed level, the master node is set with a first speed level and a second speed level lower than the first speed level. The master node monitors the presence or absence of upper communication faults, which are communication faults between the master node and the upper switch node, and the presence or absence of lower communication faults, which are communication faults between the master node and the lower switch node. In the event of an upper communication failure, the master node applies the second speed level to perform the monitoring process for the upward movement of the car. In the event of a lower communication failure, the master node applies the second speed level to perform the monitoring process for the downward movement of the car.

2. The elevator safety device according to claim 1, wherein, If the upper communication failure is not detected, the master node maintains the monitoring process of the car's upward movement at the first speed level. In the absence of detecting the lower communication failure, the master node maintains the monitoring process of the car moving downwards at the first speed level.

3. The elevator safety device according to claim 1 or 2, wherein, The master node instructs the operation management department, which manages the operation of the car, to set the highest value of the travel speed during the period when the monitoring process is performed using the second speed level to a value lower than the second speed level.

4. The elevator safety device according to claim 1 or 2, wherein, The second speed level is set below the permissible collision speed of the buffer located at the bottom of the shaft.

5. The elevator safety device according to claim 3, wherein, The second speed level is set below the permissible collision speed of the buffer located at the bottom of the shaft.

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