EP2090541B1

EP2090541B1 - Safety system for elevators

Info

Publication number: EP2090541B1
Application number: EP06834113.0A
Authority: EP
Inventors: Takuo Kugiya; Ken-Ichi Okamoto; Satoru Kato
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2006-12-06
Filing date: 2006-12-06
Publication date: 2014-08-20
Anticipated expiration: 2026-12-06
Also published as: CN101500924B; JP5053291B2; EP2090541A1; EP2090541A4; WO2008068863A1; JPWO2008068863A1; KR100985642B1; CN101500924A; KR20090087086A

Description

TECHNICAL FIELD

The present invention relates to an elevator safety apparatus that brakes a car when an overspeed of the car is detected.

BACKGROUND ART

Conventionally, elevator apparatuses have been proposed in which a car position that is detected by a car position detecting means that detects the car position continuously is corrected by a car position detecting means that detects an absolute car position intermittently. Drift from actual car position of the car position that is detected continuously is corrected by detecting the absolute car position. In these conventional elevator apparatuses, presence or absence of an overspeed is detected by comparing an overspeed disregard level that is determined based on the car position after correction and car speed (See Patent Literature 1).

[Patent Literature 1]

Japanese Patent Laid-Open No. 2003-104648 (Gazette)

DISCLOSURE OF THE INVENTION

PROBLEM TO BE SOLVED BY THE INVENTION

However, if the car has moved during a power outage, for example, even if the supply of power to each of the car position detecting means is subsequently resumed, the car position that is detected continuously cannot be corrected until the absolute car position is detected. Consequently, drift may arise between the actual car position and the detected car position, whereby the overspeed disregard level may be determined erroneously. Thus, even if the actual car speed is an overspeed, detection of the overspeed may no longer be possible.
The present invention aims to solve the above problems and an object of the present invention is to provide an elevator safety apparatus that can detect overspeed of a car more reliably.

MEANS FOR SOLVING THE PROBLEM

In order to achieve the above object, according to one aspect of the present invention, there is provided an elevator safety apparatus including: a zone detecting apparatus that detects a zone in which a car is present among a plurality of zones that are set so as to be contiguous in a direction of movement of the car, and also detects presence or absence of passage of the car through a switchover position that is positioned at a boundary between each of the zones; a movement detecting device that generates a signal that corresponds to movement of the car; and a processor that finds a speed of the car based on information from the movement detecting device, and also finds a position of the car by finding an amount of movement of the car based on information from the movement detecting device after passage of the car through the switchover position has been detected by the zone detecting apparatus, the elevator safety apparatus being characterized in that: a stepped overspeed reference that includes a plurality of zone reference levels that are determined individually for each of the zones, and a continuous overspeed reference that includes a continuous reference changing portion that changes continuously in the direction of movement of the car and that is constituted by values that are greater than or equal to the zone reference levels in each of the zones are set in the processor; and the processor identifies the zone in which the car is present as a stopping zone when the car is stopped based on information from both the zone detecting apparatus and the movement detecting device, and determines presence or absence of an overspeed in the speed of the car by comparing the zone reference level for the stopping zone and the speed of the car when the car is inside the stopping zone, and determines presence or absence of an overspeed in the speed of the car by comparing the continuous overspeed reference and the speed of the car at the position of the car when the car is outside the stopping zone.

EFFECTS OF THE INVENTION

In an elevator safety apparatus according to the present invention, because the processor determines the presence or absence of an overspeed in the speed of the car by comparing the speed of the car with the stepped overspeed reference when the car is inside a stopping zone, and the processor determines the presence or absence of an overspeed by comparing the speed of the car with the continuous overspeed reference when the car is outside the stopping zone, the presence or absence of the overspeed in the stepped overspeed reference can be determined irrespective of the exact position of the car by detecting the zone in which the car is present, even if detection of the exact position of the car becomes impossible due to the position of the car drifting during a power outage, for example, enabling an overspeed of the car to be detected more reliably. After the car has passed through one of the switchover positions that are positioned at each of the boundaries between the zones, the exact position of the car can be calculated based on the switchover position through which the car passed. Thus, the presence or absence of an overspeed can be determined using the continuous overspeed reference, enabling overspeed of the car to be detected even more reliably.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a structural diagram that shows an elevator in which a safety apparatus according to Embodiment 1 of the present invention is disposed;
Figure 2 is a graph that shows a stepped overspeed reference and a continuous overspeed reference that are set in a processor from Figure 1;
Figure 3 is a graph that shows changes in speed of a car from Figure 1 when the car moves from inside Zone B toward a lowermost floor;
Figure 4 is a graph that shows changes in the speed of the car from Figure 1 when the car moves from inside Zone B toward an uppermost floor; and
Figure 5 is a graph that shows changes in speed of a car when the car is moved away from a terminal portion in an elevator in which an elevator safety apparatus according to Embodiment 2 of the present invention is disposed.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will now be explained with reference to the drawings.

Embodiment 1

Figure 1 is a structural diagram that shows an elevator in which a safety apparatus according to Embodiment 1 of the present invention is disposed. In the figure, a car 2 and a counterweight 3 are hoistably disposed inside a hoistway 1. A hoisting machine 4 that constitutes a driving machine and a deflection sheave 5 are disposed in an upper portion of the hoistway 1. The hoisting machine 4 has: a hoisting machine main body 6; and a drive sheave 7 that is rotated by the hoisting machine main body 6. The hoisting machine main body 6 has: a motor that rotates the drive sheave 7; and a braking device that brakes rotation of the drive sheave 7.
A plurality of main ropes 8 are wound continuously around the drive sheave 7 and the deflection sheave 5. The car 2 and the counterweight 3 are suspended by the main ropes 8. The car 2 and the counterweight 3 are raised and lowered inside the hoistway 1 by rotation of the drive sheave 7. Moreover, running of the elevator is controlled by a control board (not shown) that is disposed inside the hoistway 1.
An upper pulley 9 is disposed in an upper portion of the hoistway 1, and a lower pulley 10 is disposed in a lower portion of the hoistway 1. A governing rope 11 is wound continuously around the upper pulley 9 and the lower pulley 10. A shared rope connecting portion 12 to which are connected both a first end portion and a second end portion of the governing rope 11 is disposed on the car 2. Consequently, the governing rope 11 is moved together with the car 2. The upper pulley 9 and the lower pulley 10 are rotated in response to movement of the governing rope 11.
An encoder (a movement detecting device) 13 that generates a signal that corresponds to rotation of the upper pulley 9 is disposed on a rotating shaft of the upper pulley 9. Consequently, the encoder 13 generates a signal that corresponds to movement of the car 2.
A plurality of zones (in this example, seven) that are contiguous in a direction of movement of the car 2 (Figure 2 described below) and switchover positions that are respectively positioned at respective boundaries between the zones are preset inside the hoistway 1. Detection of the zone in which the car 2 is present and detection of the whether or not the car 2 is passing through each of the switchover positions is performed by a zone detecting apparatus 14.
The zone detecting apparatus 14 has: a cam 15 that is disposed so as to be parallel to the direction of movement of the car 2; and a switch 16 that is disposed on an upper portion of the car 2, and that faces the cam 15. The switch 16 has: a switch main body 17 that is fixed to the car 2; and an operating portion 18 that is displaceable relative to the switch main body 17 (i.e., displaceable relative to the car 2).
A contact surface 19 that the operating portion 18 contacts is disposed on the cam 15. The operating portion 18 contacts the contact surface 19 while being moved together with the car 2. The contact surface 19 has: parallel portions that are parallel to the direction of movement of the car 2; and inclined portions that are contiguous with the parallel portions, and that incline relative to the direction of movement of the car 2.
When the operating portion 18 is moved while contacting the inclined portions of the contact surface 19, it is displaced relative to both the switch main body 17 and the car 2. In this example, the operating portion 18 is rotated downward when the car 2 ascends, and the operating portion 18 is rotated upward when the car 2 descends. Consequently, displacement (amount of rotation) of the operating portion 18 relative to the switch main body 17 varies depending on the position of the car 2. The switch main body 17 generates a signal that corresponds to the displacement of the operating portion 18. Moreover, the operating portion 18 may also be reciprocally displaced horizontally relative to the switch main body 17.
Information from both the encoder 13 and the switch 16 is transmitted to the processor 20. Relationships between the signal from the switch 16 and each of the zones are stored in the processor 20 as a zone setting reference. The processor 20 finds the zone in which the car 2 is present and determines whether or not the car 2 is passing through each of the switchover positions by comparing the signal from the switch 16 and the zone setting reference. In other words, the processor 20 is able to acquire information concerning the zone in which the car 2 is present and information concerning when the car 2 passed a switchover position based on the signal from the switch 16. Consequently, the processor 20 is able to acquire the zone in which the car 2 is present from the information from the switch 16, but is not able to acquire an exact position of the car 2 from the information from the switch 16.
The processor 20 is able to calculate the speed of the car 2 based on the information from the encoder 13. After the car 2 has passed through a switchover position, the processor 20 finds the amount of movement of the car 2 based on the information from the encoder 13, and calculates the position of the car 2 relative to the switchover position based on the amount of movement found. Consequently, the position of the car 2 is calculated continuously by the processor 20 after the car 2 has passed through a switchover position. A stepped overspeed reference and a continuous overspeed reference that constitute two overspeed references for detecting presence or absence of an overspeed in the speed of the car 2 are preset in the processor 20.
Figure 2 is a graph that shows a stepped overspeed reference and a continuous overspeed reference that are set in the processor 20 from Figure 1. In the figure, the respective zones that are set in the hoistway 1 are contiguous in order of Zones A through G from a floor portion toward a top portion of the hoistway 1. The respective switchover positions are also set at the respective boundaries between each of Zones A through G. Moreover, a lowermost floor is positioned inside Zone A, and an uppermost floor is positioned inside Zone G.
A stepped overspeed reference 21 includes a plurality of zone reference levels (in this example, seven) that have been determined individually for each of Zones A through G. In other words, a constant zone reference level is set in the stepped overspeed reference 21 for each of the Zones A through G. Values of the zone reference levels are different values in each of the Zones A through G. Consequently, the stepped overspeed reference 21 is an overspeed reference that changes in steps in each of the Zones A through G. Moreover, the values of the zone reference levels are larger values in zones that are closer to an intermediate portion of the hoistway 1, and are smaller values in zones that are closer to the top portion and the floor portion (i.e., terminal portions) of the hoistway 1. The value of each of the zone reference levels is set such that the speed of the car 2 is always below the zone reference level inside the zone when normal acceleration has been performed on a car 2 that has stopped inside the zone (i.e., such that the speed of the car 2 will not reach the zone reference level before the car 2 leaves the zone).
The continuous overspeed reference 22 is an overspeed reference that is smoothly continuous in the direction of movement of the car 2, and is expressed as a function of the position of the car 2. The continuous overspeed reference 22 is constituted by values that are greater than or equal to the zone reference levels of the stepped overspeed reference 21 in all of Zones A through G. The continuous overspeed reference 22 includes: continuous reference changing portions 23 that change continuously in the direction of movement of the car 2 in first and second continuously variable regions that are respectively adjacent to the floor portion and the top portion of the hoistway 1; and a continuous reference unchanging portion 24 is continuous at an unmodified constant value in the direction of movement of the car 2 in a continuously invariable region that is between each of the continuously variable regions. In this example, the continuously variable region that is adjacent to the floor portion (the first continuously variable region) is a region that is constituted by Zones A through C, and the continuously variable region that is adjacent to the top portion (the second continuously variable region) is a region that is constituted by the Zones E through G. The continuously invariable region is a region that is constituted by Zone D. The values of the continuous reference changing portions 23 become continuously smaller as they approach the terminal portions of the hoistway 1.
Moreover, changes in the speed of the car 2 as the car 2 moves from a first position toward a second position between the top portion and the floor portion of the hoistway 1 during normal operation are set as normal running patterns 26 in the processor 20. The speed of the car 2 will not exceed the normal running patterns 26 as long as the car 2 is moving normally.
The processor 20 identifies the zone in which the car 2 is present as a stopping zone if the car 2 stops due to a stopping command from the control board, or due to a power outage, for example. When the car 2 is within a stopping zone, the processor 20 determines the presence or absence of an overspeed in the speed of the car 2 by comparing the speed of the car 2 with the zone reference levels for the stopping zone in the stepped overspeed reference 21. In addition, when the car 2 leaves the stopping zone, the processor 20 determines the presence or absence of an overspeed in the speed of the car 2 at a calculated position of the car 2 by comparing the speed of the car 2 with the continuous overspeed reference 22.
In other words, the processor 20 selects either the stepped overspeed reference 21 or the continuous overspeed reference 22 based on information from both the encoder 13 and the switch 16 and determines the presence or absence of an overspeed in the speed of the car 2 by comparing the selected overspeed reference and the speed of the car 2. In other words, the processor 20 determines the presence or absence of an overspeed in the speed of the car 2 by processing information from both the encoder 13 and the switch 16.
The processor 20 controls operation of the hoisting machine 4 based on the determined result of the presence or absence of the overspeed. In other words, the processor 20 outputs a braking command to the hoisting machine 4 to make the braking device perform a braking action if a determination has been made that the speed of the car 2 has reached an overspeed, and outputs a releasing command to the hoisting machine 4 to release the braking action of the braking device if it has been determined that the speed of the car 2 is lower than an overspeed.
Next, operation will be explained. Figure 3 is a graph that shows changes in the speed of the car 2 from Figure 1 when the car moves from inside Zone B toward a lowermost floor. As shown in the figure, if the car 2 has been stopped inside Zone B, the stepped overspeed reference 21 is selected by the processor 20 from among the stepped overspeed reference 21 and the continuous overspeed reference 22. At this point, Zone B in which the car 2 has been stopped is identified as the stopping zone by the processor 20.
When movement of the car 2 is subsequently commenced, the speed of the car 2 is changed in accordance with the running pattern 31 while the car 2 is being moved toward the lowermost floor. When the car 2 is moved inside the stopping zone, the stepped overspeed reference 21 is constantly selected by the processor 20. In other words, when the car 2 is moved inside the stopping zone, the path 32 of the overspeed reference that is selected by the processor 20 follows the stepped overspeed reference 21. At this point, the speed of the car 2 is compared with the zone reference level in the stopping zone of the selected stepped overspeed reference 21, and presence or absence of an overspeed in the speed of the car 2 is determined by the processor 20.
When the car 2 is subsequently moved further toward the lowermost floor and passes through a switchover position (i.e., when the car 2 leaves the stopping zone (Zone B)), the overspeed reference that is selected by the processor 20 is switched over from the stepped overspeed reference 21 to the continuous overspeed reference 22. In other words, when the car 2 is moved through Zone A outside the stopping zone, the path 32 of the overspeed reference that is selected by the processor 20 will follow the continuous overspeed reference 22.
When the car 2 is moved through Zone A outside the stopping zone after passing through the switchover position, a position of the car 2 that uses the switchover position as a reference is calculated in the processor 20 using information from the encoder 13. At this point, the speed of the car 2 is compared with the continuous overspeed reference 22 at the calculated position of the car 2, and presence or absence of an overspeed in the speed of the car 2 is determined by the processor 20.
If the speed of the car 2 has reached an overspeed, a braking action of the braking device of the hoisting machine 4 is performed by control from the processor 20, and if the speed of the car 2 has not reached an overspeed, the brake release state of the braking device is maintained by control from the processor 20.
When the car 2 arrives at the lowermost floor, stopping of the car 2 is detected by the processor 20 based on the information from the encoder 13. At that point, the overspeed reference that is selected by the processor 20 is switched back over from the continuous overspeed reference 22 to the stepped overspeed reference 21. Zone A, which includes the lowermost floor at which the car 2 is stopped, is freshly identified as the stopping zone by the processor 20.
Figure 4 is a graph that shows changes in the speed of the car 2 from Figure 1 when the car moves from inside Zone B toward an uppermost floor. As shown in the figure, when the car 2 moves toward the uppermost floor from inside Zone B, if the car 2 has been stopped inside Zone B, the stepped overspeed reference 21 is also selected and Zone B is also identified as the stopping zone by the processor 20.
When movement of the car 2 is subsequently commenced, the speed of the car 2 is changed in accordance with the running pattern 31 while the car 2 is being moved toward the uppermost floor. When the car 2 is moved inside the stopping zone, the stepped overspeed reference 21 is constantly selected by the processor 20. In other words, when the car 2 is moved inside the stopping zone, the path 34 of the overspeed reference that is selected by the processor 20 follows the stepped overspeed reference 21. At this point, the speed of the car 2 is compared with the zone reference level in the stopping zone of the selected stepped overspeed reference 21, and presence or absence of an overspeed in the speed of the car 2 is determined by the processor 20.
When the car 2 is subsequently moved further toward the uppermost floor and passes through a switchover position, i.e., when the car 2 leaves the stopping zone (Zone B), the overspeed reference that is selected by the processor 20 is switched over from the stepped overspeed reference 21 to the continuous overspeed reference 22. In other words, when the car 2 is moved outside the stopping zone, the path 34 of the overspeed reference that is selected by the processor 20 will follow the continuous overspeed reference 22.
After the car 2 has passed through a switchover position, a position of the car 2 that has the switchover position as a reference is constantly calculated in the processor 20 using information from the encoder 13. Because the car 2 passes through a plurality of switchover positions before arriving at the uppermost floor, the switchover position that constitutes a calculating reference for the position of the car 2 is updated to the most recent switchover position that the car 2 has passed through each time the car 2 passes through a switchover position.
When the position of the car 2 is calculated, the speed of the car 2 is compared with the continuous overspeed reference 22 at the calculated position of the car 2, and presence or absence of an overspeed in the speed of the car 2 is determined by the processor 20. Subsequent operation is similar to when the car 2 is moved to the lowermost floor.
In an elevator safety apparatus of this kind, because a stepped overspeed reference 21 that includes a plurality of zone reference levels that have been determined individually for each of Zones A through G, and a continuous overspeed reference 22 that is constituted by values that are greater than or equal to the zone reference levels in all of Zones A through G are preset in a processor 20, and the processor 20 determines the presence or absence of an overspeed in the speed of the car 2 by comparing the speed of the car 2 with the stepped overspeed reference 21 when the car 2 is inside a stopping zone, and the processor 20 determines the presence or absence of an overspeed in the speed of the car 2 by comparing the speed of the car 2 with the continuous overspeed reference 22 when the car 2 is outside the stopping zone, even if the position of the car 2 drifts during a power outage, for example, and detection of the exact position of the car 2 becomes impossible after the restoration of the power supply, the presence or absence of the overspeed in the stepped overspeed reference 21 can be determined irrespective of the exact position of the car 2 by detecting the zone in which the car 2 is present, enabling an overspeed of the car 2 to be detected more reliably. After the car 2 has passed through one of the switchover positions that are positioned at each of the boundaries between Zones A through G, the exact position of the car 2 can be calculated based on the switchover position through which the car 2 passed. Thus, the presence or absence of an overspeed can be determined using the continuous overspeed reference 22, enabling overspeed of the car 2 to be detected even more reliably.
Because the zone detecting apparatus 14 has: a cam 15 that is disposed so as to be parallel to the direction of movement of the car 2; and a switch 16 that is disposed on the car 2, and that includes an operating portion 18 that is displaced relative to the car 2 by being moved while contacting the cam 15, and the switch 16 generates a signal that corresponds to the amount of displacement of the operating portion 18, the zone detecting apparatus 14 can be made with a simple configuration. The processor 20 can also find the zone in which the car 2 is present more reliably, also enabling the presence or absence of passage of the car 2 through the switchover positions to be determined more reliably.
Moreover, in the above example, the overspeed reference that is selected by the processor 20 is switched over from the continuous overspeed reference 22 to the stepped overspeed reference 21 if the processor 20 detects that the car 2 has stopped, but the overspeed reference that is selected by the processor 20 may also be switched over from the continuous overspeed reference 22 to the stepped overspeed reference 21 if the processor 20 detects that movement of the car 2 has commenced.
In the above example, the speed of the car 2 is found by the processor 20 based on the information from the encoder 13, but the processor 20 may also acquire the speed of the car 2 based on information from a speed detecting device that is separate from the encoder 13. In that case, the speed detecting device generates a signal that corresponds to the speed of the car 2. Generators that generate power from the movement of the car 2, etc., can be used as speed detecting devices, for example. Overspeed of the car 2 can thereby also be determined more reliably.
In the above example, the relationship between the signal from the switch 16 and each of the switchover positions is not changed in the processor 20, but updating of each of the switchover positions may also be made possible by performing a measuring run in which the car 2 is moved from the first position toward the second position between the uppermost floor and the lowermost floor of the hoistway 1.
In that case, the processor 20 can output a command to perform the measuring run to the control board regularly or irregularly. The control board performs the measuring run by receiving the command from the processor 20. Updating of each of the switchover positions is performed by finding new switchover positions based on the information from the zone detecting apparatus 14 during the measuring run, and replacing the former switchover positions with the switchover positions that are found.
During the measuring run, the presence or absence of abnormalities in the encoder 13 is determined by the processor 20. The determination of the presence or absence of abnormalities in the encoder 13 is performed by comparing the distance traveled by the car 2 that is found based on the information from the encoder 13 and a set distance traveled that has been preset. The processor 20 determines whether or not updating of each of the switchover positions based on the information from the zone detecting apparatus 14 is required only if it determines that the encoder 13 is operating normally. The determination of whether or not updating of each of the switchover positions is required is performed by comparing a difference between the new switchover position that has been found based on the information from the zone detecting apparatus 14 and the former switchover position and a threshold value that has been preset. Specifically, if the difference between the new switchover position and the former switchover position is less than or equal to the threshold value, it is determined that updating is not required, and if greater than the threshold value, it is determined that updating is required.
Because each of the switchover positions in the processor 20 can be updated in this manner, the occurrence of drift between each of the switchover positions that are recognized by the processor 20 and each of the actual switchover positions can be prevented, enabling overspeed of the car 2 to be determined more reliably.

Embodiment 2

In the above example, the stepped overspeed reference 21 and the speed of the car 2 are compared when the car 2 is within a stopping zone, and the continuous overspeed reference 22 and the speed of the car 2 are compared when the car 2 is outside the stopping zone, irrespective of the direction of movement of the car 2, but presence or absence of an overspeed may also be detected by a separate overspeed reference when the direction of movement of a car 2 is away from a terminal portion of a hoistway 1, irrespective of the zone in which the car 2 is present.
Specifically, Figure 5 is a graph that shows changes in speed of the car 2 when the car 2 is moved away from a terminal portion in an elevator in which an elevator safety apparatus according to Embodiment 2 of the present invention is disposed. Changes in the speed of the car 2 when the car is moved from inside Zone B toward an uppermost floor are shown in Figure 5.
First and second terminal regions that are respectively adjacent to a floor portion and a top portion (respective terminal portions); and an intermediate region that is positioned between each of the terminal regions are set in a hoistway 1. The first terminal region is constituted by Zones A through C, and the second terminal region is constituted by Zones E through G. The intermediate region is constituted by Zone D.
The processor 20 finds the direction of movement of the car 2 based on the information from the encoder 13. When the car 2 is present in one of the terminal regions and the direction of movement of the car 2 is toward the intermediate region, the processor 20 selects a maximum value of the continuous overspeed reference as a maximum value reference level, and determines the presence or absence of an overspeed in the speed of the car 2 by comparing the maximum value reference level and the speed of the car 2. Moreover, when the car 2 is in the intermediate region, or the direction of movement of the car 2 is away from the intermediate region (i.e., a direction in which the car 2 approaches one of the terminal portions), the processor 20 performs a process similar to that of Embodiment 1 above.
Next, operation will be explained. If the car 2 has been stopped in Zone B, Zone B is identified as the stopping zone by the processor 20. When movement of the car 2 is subsequently commenced, the speed of the car 2 and the direction of movement of the car 2 are calculated by the processor 20. When the direction of movement of the car 2 is toward the intermediate region (Zone D), a maximum value of the continuous overspeed reference 22 is selected by the processor 20 as a maximum value reference level. In other words, when the car 2 is moved inside a terminal region and the direction of movement of the car 2 is toward the intermediate region, the path 41 of the overspeed reference that is selected by the processor 20 follows the stepped overspeed reference 21. At this point, the presence or absence of an overspeed in the speed of the car 2 is determined by the processor 20 by comparing the maximum value reference level and the speed of the car 2.
When the car 2 subsequently leaves the terminal region and enters the intermediate region, the overspeed reference that is selected by the processor 20 is switched over from the maximum value reference level to a continuous overspeed reference. Subsequent action is similar to that of Embodiment 1.
In an elevator safety apparatus of this kind, because the direction of movement of the car 2 is found by the processor 20 based on the information from the encoder 13, and presence or absence of an overspeed in the speed of the car 2 is determined by the processor 20 by comparing the maximum value of the continuous overspeed reference 22 and the speed of the car 2 irrespective of the zone in which the car 2 is present when the car 2 is in a terminal region and the direction of movement of the car 2 is toward the intermediate region, the overspeed reference can be set to a high level when there is no risk that the car 2 will collide with the floor portion or the top portion (terminal portions). Thus, even if the car 2 is shaken by passengers inside the car 2, for example, overspeed of the car 2 can be prevented from being detected erroneously due to the shaking of the car 2.

Claims

An elevator safety apparatus comprising:
a zone detecting apparatus (14) that detects a zone in which a car (2) is present among a plurality of zones that are set so as to be contiguous in a direction of movement of the car (2), and also detects presence or absence of passage of the car (2) through a switchover position that is positioned at a boundary between each of the zones;

a movement detecting device (13) that generates a signal that corresponds to movement of the car (2); and

a processor (20) that finds a speed of the car (2) based on information from the movement detecting device (13), and also finds a position of the car (2) by finding an amount of movement of the car (2) based on information from the movement detecting device (13) after passage of the car (2) through the switchover position has been detected by the zone detecting apparatus (14),

the elevator safety apparatus being characterized in that:
a stepped overspeed reference (21) that includes a plurality of zone reference levels that are determined individually for each of the zones, and a continuous overspeed reference (22) that includes a continuous reference changing portion (23) that changes continuously in the direction of movement of the car (2) and that is constituted by values that are greater than or equal to the zone reference levels in each of the zones are set in the processor (20); and

the processor (20) identifies the zone in which the car (2) is present as a stopping zone when the car (2) is stopped based on information from both the zone detecting apparatus (14) and the movement detecting device (13), and determines presence or absence of an overspeed in the speed of the car (2) by comparing the zone reference level for the stopping zone and the speed of the car (2) when the car (2) is inside the stopping zone, and determines presence or absence of an overspeed in the speed of the car (2) by comparing the continuous overspeed reference (22) and the speed of the car (2) at the position of the car (2) when the car (2) is outside the stopping zone.
An elevator safety apparatus comprising:
a zone detecting apparatus (14) that detects a zone in which a car (2) is present among a plurality of zones that are set so as to be contiguous in a direction of movement of the car (2), and also detects presence or absence of passage of the car (2) through a switchover position that is positioned at a boundary between each of the zones;

a speed detecting device that detects a speed of the car (2);

a movement detecting device (13) that generates a signal that corresponds to movement of the car (2); and

a processor (20) that acquires the speed of the car (2) from the speed detecting device, and also finds a position of the car (2) by finding an amount of movement of the car (2) based on information from the movement detecting device (13) after passage of the car (2) through the switchover position has been detected by the zone detecting apparatus (14),

the elevator safety apparatus being characterized in that:
a stepped overspeed reference (21) that includes a plurality of zone reference levels that are determined individually for each of the zones, and a continuous overspeed reference (22) that includes a continuous reference changing portion (23) that changes continuously in the direction of movement of the car (2) and that is constituted by values that are greater than or equal to the zone reference levels in each of the zones are set in the processor (20); and

the processor (20) identifies the zone in which the car (2) is present as a stopping zone when the car (2) is stopped based on information from both the zone detecting apparatus (14) and the speed detecting device, and determines presence or absence of an overspeed in the speed of the car (2) by comparing the zone reference level for the stopping zone and the speed of the car (2) when the car (2) is inside the stopping zone, and determines presence or absence of an overspeed in the speed of the car (2) by comparing the continuous overspeed reference (22) and the speed of the car (2) at the position of the car (2) when the car (2) is outside the stopping zone.
An elevator safety apparatus according to either of Claims 1 or 2, characterized in that:
the zone detecting apparatus has:
a cam (15) that is disposed so as to be parallel to the direction of movement of the car (2); and

a switch (16) that includes an operating portion (18) that is displaced relative to the car (2) by being moved while contacting the cam (15), that is disposed on the car (2), and that generates a signal that corresponds to displacement of the operating portion (18), and

the processor (20) finds the zone in which the car (2) is present and determines presence or absence of passage of the car (2) through the switchover position based on information from the switch (16).
An elevator safety apparatus according to either of Claims 1 or 2, characterized in that:
the processor (20) can output a command to an elevator control board to perform a measuring run that moves the car (2) from a first position toward a second position between an uppermost floor and a lowermost floor inside the hoistway (1); and

the processor (20) determines presence or absence of abnormalities in the movement detecting device (13) based on information from the movement detecting device (13) during the measuring run, and determines whether or not updating of the switchover position is required based on information from the zone detecting apparatus (14) only if a determination has been made that the movement detecting device (13) is operating normally.
An elevator safety apparatus according to either of Claims 1 or 2, characterized in that:
predetermined terminal regions that are respectively adjacent to terminal portions of the hoistway (1) and an intermediate region that is positioned between the terminal regions are set inside the hoistway (1);

the processor (20) can find the direction of movement of the car (2) based on information from the movement detecting device (13); and

the processor (20) determines presence or absence of an overspeed in the speed of the car (2) by comparing a maximum value of the continuous overspeed reference (22) and the speed of the car (2) if the car (2) is inside a terminal region and the direction of movement of the car (2) is toward the intermediate region.