Technical Field
[0001]
The present invention relates to an elevator and a
rescue operation control method.
Background Art
[0002]
A conventional elevator enables a car connected to a
rope to move up and down by rotating an electric motor from
an electric power converter and moving the rope in the
vertical direction through a sheave coupled with the
electric motor. When part of a drive system, such as this
electric power converter, this electric motor or an encoder
connected to the electric motor, fails, the elevator stops.
When the position where the car of the elevator stopped is
between the floors and a passenger is in the car at this
time, a state in which the passenger is trapped in the car
occurs. Since the car does not move in this state, the
safety of the passenger is guaranteed, but the passenger
experiences discomfort.
[0003]
3
A method for rescuing the passenger trapped by such
failure of the drive system is generally performed by a
maintenance worker. In particular, when the weight in the
car is not balanced with a counterweight, the passenger is
rescued by moving the car to the nearest floor by releasing
the brake manually and using the imbalance between the car
and the counterweight.
[0004]
On the other hand, since the above method is
performed after waiting for the arrival of the maintenance
worker, a waiting time occurs for rescuing the passenger.
As a method for solving this problem, PTL 1 discloses a
method for rescuing early by using a dedicated terminal
which automatically releases a brake.
Citation List
Patent Literature
[0005]
PTL 1: WO 2009/013821
Summary of Invention
Technical Problem
[0006]
PTL 1 suggests that the voltage at the starting time
is linearly increased until the movement of the car is
detected. However, if the responsiveness of a coil used
4
for the brake is low, a voltage command reaches a value, at
which the brake can be sufficiently opened, when the brake
starts to open and the car moves. Thus, there is a
possibility of causing a sudden velocity increase of the
car.
[0007]
In light of the above circumstances, the present
invention provides an elevator and a rescue operation
method for the elevator capable of preventing sudden
acceleration of a passenger car at a time of starting to
move during brake release operation.
Solution to Problem
[0008]
In order to solve the above-mentioned problems, the
present invention provides an elevator including: a
passenger car; a rope whose one end is connected to the
passenger car; a counterweight connected to an other end of
the rope; a sheave around which the rope is wound; a
solenoid coil which weakens a braking force as a current
supplied increases; a brake device which brakes movement of
the passenger car by applying the braking force to the
sheave; a brake power supply which supplies the current to
the solenoid coil; a moving velocity detection means which
detects a moving velocity of the passenger car; and a
5
controller which controls the current supplied by the brake
power supply according to the moving velocity of the
passenger car detected by the moving velocity detection
means, in which the controller moves the passenger car by
an imbalance of weights between the passenger car and the
counterweight while the braking force is generated by the
brake device, by transmitting, to the brake power supply, a
command for increasing the current supplied to the solenoid
coil by a predetermined value every time a predetermined
time elapses when the passenger car is stopped and by
transmitting, to the brake power supply, a command for
stopping increasing the current supplied to the solenoid
coil when a velocity change of the passenger car is
detected by the moving velocity detection means.
[0009]
Moreover, the present invention provides a rescue
operation control method for an elevator including: a
passenger car; a rope whose one end is connected to the
passenger car; a counterweight connected to an other end of
the rope; a sheave around which the rope is wound; a
solenoid coil which weakens a braking force as a current
supplied increases; and a brake device which brakes
movement of the passenger car by applying the braking force
to the sheave, includes: increasing the current supplied to
the solenoid coil by a predetermined value every time a
6
predetermined time elapses when the passenger car is
stopped in emergency and a passenger is in the passenger
car; and moving the passenger car to a floor where the
passenger can get off by an imbalance of weights between
the passenger car and the counterweight while the braking
force is generated by the brake device, by stopping
increasing the current supplied to the solenoid coil when a
velocity change of the passenger car is detected.
Advantageous Effects of Invention
[0010]
According to the present invention, it is possible to
prevent sudden acceleration of the passenger car at the
time of starting to move during the brake release operation.
Brief Description of Drawings
[0011]
[FIG. 1] FIG. 1 is a block diagram showing the entire
configuration of an elevator according to the present
invention.
[FIG. 2] FIG. 2 is a block diagram showing the a
series of processing of the braking force control unit 20
in FIG. 1.
[FIG. 3] FIG. 3 is a timing chart showing one example
of the outline of the behavior of the elevator according to
7
the present invention.
[FIG. 4] FIG. 4 is a timing chart showing another
example of the outline of the behavior of the elevator
according to the present invention.
[FIG. 5] FIG. 5 is a flow diagram showing a rescue
operation control method for the elevator according to the
present invention.
Description of Embodiments
[0012]
Hereinafter, embodiments of the present invention
will be described in detail with reference to the drawings.
Examples
[0013]
FIG. 1 is a block diagram showing the entire
configuration of an elevator according to an example. The
movement of a car 104 of the elevator is controlled by an
elevator controller 100. The elevator controller 100
includes a braking force control unit 20 in addition to an
elevator control unit 2 which controls the operation of the
elevator.
[0014]
The car 104 moves in a hoistway formed in the
building across a plurality of floors. Although not shown
8
in FIG. 1, the car 104 is connected to a counterweight for
balancing with the car 104 through a rope. The car 104 is
provided with a passenger car side door (not shown) which
engages a riding side door (now shown) to open and close.
The movement of the car 104 is performed by a sheave being
driven by an electric motor 103. Electric power for the
driving is supplied to the electric motor 103 by an
electric power converter 101. The electric power converter
101 outputs electric power for controlling the electric
motor according to a car position control command of the
elevator controller 100. Moreover, a pulse generator such
as an encoder is attached, and the elevator controller 100
counts the pulses generated by the rotation of the electric
motor 103, thereby calculating the velocity of the electric
motor 103, the hoistway moving direction, the position and
the moving distance of the car 104, and the like. To brake
the passenger car, the elevator controller 100 outputs a
brake power supply stop command and a motive power supply
stop command. When received these stop commands, a brake
power supply actuates a brake device 102 and a motive power
supply cuts off the power supply to the electric power
converter 101 to brake the car 104. The brake power supply
and the motive power supply are circuits constituted by
electromagnetic contactors called contactors.
[0015]
9
The brake device 102 is constituted by a brake pad
for braking the sheave by frictional sliding, a solenoid
coil for pulling up the brake pad to secure a gap between
the sheave and the brake pad, and an iron core (core).
Normally, when electric power is supplied to the solenoid
coil, the brake pad is pulled up by electromagnetic force,
and the sheave becomes free from the constraint by the
brake pad and freely rotatable. Power is supplied to the
solenoid coil through a relay from the brake power supply.
Moreover, the brake device 102 is constituted so as to be
capable of changing the braking force by a circuit which
controls a current (brake current) flowing to the solenoid
coil by a brake current control circuit 21.
[0016]
The brake current control circuit 21 is constituted
by a converter, such as an inverter circuit or a chopper
circuit, which controls the current or the voltage, a hall
CT which detects the brake current, and a controller for
controlling the brake current, receives, from the elevator
controller 100, a command value (brake current command) of
the current flowing to the solenoid coil, and controls the
brake current to that command value. Note that, in the
present example, as one example for changing the braking
force, the brake mechanism which changes the braking force
according to the current by using the solenoid coil has
10
been exemplified. However, for example, a brake, which
changes the braking force according to the distance by
using a direct acting type actuator, or a brake (shoe brake
or the like), which changes the braking force according to
the rotation angle by using a rotation mechanism, may be
used. In general, the type of the brake does not matter as
long as the braking force of the brake is changed according
to a certain command.
[0017]
A scale sensor 4 is used to detect the number of
passengers in the car. The scale sensor 4 is used to
calculate the torque necessary to compensate for the weight
difference between the car and the counterweight during
normal operation. When the car floor surface is metal, the
scale sensor uses a method for estimating the weight from
the amount of deflection of the car floor surface with a
proximity sensor or the like provided to the car frame.
[0018]
A position sensor 5 is a door zone sensor which
detects whether or not the elevator is at a position where
the door can be opened by detecting a detection plate 6.
[0019]
A safety controller 1 is a controller constituting a
safety system, which brakes the car 104 by shutting off the
brake power supply and the motive power supply
11
independently from the elevator controller 100. The safety
controller 1 is mainly constituted by a central processing
unit (CPU) which executes a series of processing, and
additionally has a watchdog timer for detecting abnormality
of the CPU and a circuit for monitoring power supply
abnormality. Moreover, to detect processing abnormality of
the CPU, the safety controller 1 may have the constitution
which performs mutual comparison by duplicating the CPU in
some cases.
[0020]
The inputs of the safety controller 1 are constituted
by a means 7 for detecting the position, velocity and
acceleration of the car and a means which detects the
actuation of a safety device of the elevator. The means 7
for detecting the position, velocity and acceleration of
the car is, for example, a pulse generator which outputs
pulses according to the position of the car. In this
example, one with an encoder attached to a governor is
shown in the drawing. Besides that, this means 7 only
needs to be a means which can detect an absolute or
relative position of the car, such as a type which detects
the movement of the passenger car by directly pressing a
roller against a guide rail, or a type which magnetizes a
rail for the detection.
[0021]
12
The outputs of the safety controller 1 are
constituted by a brake power supply shut-off output 9, a
motive power supply shut-off output 10, and a car position
and velocity information output 23 detected by the safety
controller 1. The brake power supply shut-off output 9 is
an output for shutting off the brake power supply to
actuate the brake device 102. Similarly, the motive power
supply shut-off output 10 is also an output for stopping
the electric motor 103 by shutting off the electric power
source of the electric power converter 101. All the
outputs are used to brake the car.
[0022]
FIG. 2 is a block diagram showing the series of
processing of the braking force control unit 20 in FIG. 1,
and the outline of the series of processing of the braking
force control unit 20 will be described with reference to
this drawing. A rescue operation start detection
processing unit 30 is a processing unit which detects a
rescue operation start command transmitted from the
elevator control unit 2 of the elevator controller 100, and
transmits the start or stop of the rescue operation
identified by the rescue operation start command to a brake
current command creation processing unit 32. A car
velocity detection processing unit 31 receives the car
position and velocity information output 23 inputted from
13
the safety controller 1, detects the current car velocity
of the self-equipment in the hoistway, and outputs the
detected car velocity. Based on the rescue operation start
command outputted from the rescue operation start detection
processing unit 30, the brake current command creation
processing unit 32 creates a brake current command and
outputs the created brake current command to the brake
current control circuit 21. The brake current command
creation processing unit 32 also changes the brake current
command based on the car velocity outputted from the car
velocity detection processing unit 31. To create a brake
command, the brake current command creation processing unit
32 acquires different adjustment parameters depending on
the type of brake from a model information database (DB) 33.
Specifically, these adjustment parameters include a time
for stopping the increase of the current command value for
a certain period of time after the current is increased to
a certain value to wait for the change in the magnetic flux.
The change in the magnetic flux which changes the brake
torque is delayed from the change in the current command.
Thus, in consideration of that, a time for stopping the
increase of the current command value for a certain period
of time after the current is increased to a certain value
is provided to wait for the change in the magnetic flux.
Since the change in the current command value and the delay
14
in the magnetic flux change are different depending on the
structure and size of the brake, this information is
acquired from the model information database (DB).
[0023]
FIG. 3 is a timing chart showing one example of the
outline of the behavior of the elevator according to
Example 1. Specifically, FIG. 3 shows the relationships
among the brake current command i* created by the brake
current command creation processing unit 32, the brake
current i flowing to the solenoid coil, the brake torque T
acting between the brake pad and the sheave, and the car
velocity with the horizontal axes as time. Also, for
convenience of explanation, the time axis is divided into
five sections from (a) to (e). Hereinafter, the basic
behavior method will be described in order from the section
(a).
[0024]
In the section (a), the brake current command i* is
in a state of zero, the brake torque T is in a state in
which sufficient torque is given to constrain the sheave,
and the car velocity is zero.
[0025]
In the section (b), the brake current command i* is
increased stepwise, and the brake current i flowing to the
solenoid coil also increases accordingly. Herein, the
15
purpose of increasing the brake current command i* (or the
brake current i) is to weaken the brake torque T, which is
the braking force of the brake, by increasing the brake
current i, and set the torque generated from the imbalance
between the car and the counterweight and the braking force
of the brake into an equilibrium state. In the section (b),
the behavior is that, as the brake current i increases, an
electromagnetic force is generated in the solenoid coil,
and the brake torque T is weakened. In this state, the
brake torque T is in a state of being greater than the
torque generated by the imbalance between the car and the
counterweight so that the car does not move and the car
velocity V remains at zero. Moreover, the command is made
stepwise at this time because the responsiveness of the
brake is taken into consideration. Normally, the actuator
such as the brake device 102 is constituted by an iron core
and a coil. However, since the magnetic permeability of
the iron core is low, the change in the magnetic flux is
slower than the change in the current. As a result, the
brake device 102, which is the actuator, behaves in a
direction to open with a delay to the current command. For
this reason, as shown in the section (b) in FIG. 3, the
increase of the current is stopped for a certain period of
time after the current is increased to a certain value to
wait for the change in the magnetic flux. The time to stop
16
the increase of the current is equal to or greater than the
delay time of the magnetic flux change from the change in
the current. Thus, the current command can be easily
followed.
[0026]
On the contrary, if the current command is not made
stepwise but given with a certain inclination, the response
delay of the magnetic flux change is long from the change
in the current command. Thus, the behavior of the actuator
cannot follow the current command and behaves with a delay
from the current command. When the actuator behaves in
this way, the current command is in a state of being
further applied a large value at the timing the car starts
to move. As a result, there is a possibility that the
brake device 102 further opens and sudden acceleration
occurs.
[0027]
The section (c) is the timing from increasing the
brake current command i* until the car moves and the car
velocity V is detected. As previously mentioned, there is
a response delay of the magnetic flux change from the
change in the current command. Thus, there is a time as
this section (c) from that the brake torque T changes until
the car velocity V is detected.
[0028]
17
The section (d) shows a state in which the brake
current command i* is fixed at the timing the car velocity
V is detected. The detection of the car velocity V
indicates a state in which the brake torque T is less than
the torque generated from the imbalance between the car and
the counterweight. By fixing the brake current command at
this time, it is possible to create a state in which the
car is accelerated by the difference between the brake
torque T, which is the braking force of the brake, and the
torque generated from the imbalance between the car and the
counterweight. Moreover, it is possible to increase the
velocity of the car with a smaller acceleration than in a
state in which the brake is completely released.
[0029]
The section (e) shows a state in which the brake
torque T, which is the braking force of the brake, is
continuously controlled by continuously changing the brake
current command as a square wave without suddenly
increasing the change amount per unit time according to the
detected car velocity V, and the car is being controlled at
a constant velocity. In a conventional method for
controlling the car velocity by opening and closing the
brake, the brake torque is repeatedly applied as a square
wave, and the change amount of the brake torque T per unit
time becomes large. As a result, the velocity change of
18
the car per unit time becomes also large, and vibration
occurs in the car. In contrast, in the method of the
present example, the brake current is continuously
controlled, and the brake torque T is continuously changed.
Thus, the change amount of the brake torque T becomes small
so that it is possible to prevent sudden acceleration of
the passenger car at the time of starting to move and to
reduce the vibration of the car.
[0030]
FIG. 4 is a timing chart showing another example of
the outline of the behavior of the elevator according to
the present invention, showing the operation method for
decelerating the velocity in the section (d) in FIG. 3 to
once stop the car and repeating again from the section (a).
The feature of this mode is that the brake torque is
changed according to the brake current. Not only the
constant velocity operation, but also the operation may be
repeated again after stopping once every time in this way.
The merit of behaving in this way is that it is not
necessary to consider the influence on the brake pad when
running continuously. As shown in Fig. 3, when the
constant velocity operation is applied to the elevator for
long distance, the brake pad continuously wears out during
the constant velocity running. In particular, since there
is concern that the temperature of the brake pad portion
19
will rise during a long-time running, there is a
possibility that the friction characteristics change and
braking may not be secured. Therefore, by once stopping
and completing the operation, it is possible to suppress
the temperature rise of the brake pad portion and to
continue the main operation while the braking force of the
brake is secured.
[0031]
Note that control for stopping once when the brake is
released several times in combination with the series of
processing in FIGS. 3 and 4 may be performed. FIG. 5 is a
flow diagram showing one example of a rescue operation
method for the elevator according to the present invention
and shows a flowchart of a series of processing executed by
the brake current command creation processing unit 32. In
Step S101, the brake current command creation processing
unit 32 judges ON (start)/OFF (stop) of the rescue
operation start command outputted from the rescue operation
start detection processing unit 30. When the rescue
operation start command is OFF, the processing ends. When
the rescue operation start command is ON, the processing
proceeds to Step S102. The condition under which the
rescue operation start command is ON is normally set to
when a passenger is trapped in the car and the motor or the
like cannot be driven due to some abnormality, or the like.
20
Note that, as a behaving condition at this time, it is also
necessary for the brake to behave normally. The condition
under which the rescue operation start command is OFF is
set to when the car reaches the door openable position on
the nearest floor during usual operation or during carrying
out the rescue operation.
[0032]
In Step S102, the brake current command creation
processing unit 32 decides whether or not the car velocity
V is zero. When the car velocity V is zero, the car is in
a stopped state by the brake so that the processing
proceeds to step S103. Then, the brake current i is
increased to weaken the brake torque T, which is the
braking force of the brake, and the brake current command
i* is increased to bring the torque generated from the
imbalance between the car and the counterweight and the
braking force of the brake into an equilibrium state.
Moreover, by staying for a predetermined time, the
influence of the portion due to the response delay of the
brake is eliminated. After staying for a predetermined
time, the processing returns to Step S101. When the car
velocity V is not zero, the processing proceeds to Step
S104. Note that the value for increasing the brake current
command i* is determined according to the resolution for
controlling the brake. In Step S104, the brake current
21
command i* is fixed. By fixing the brake current command
i* in a situation where the car velocity is not zero, it is
possible to secure a slipping state in which the brake pad
and the sheave frictionally move without completely
releasing the brake.
[0033]
In Step S105, whether or not the car velocity V is
greater than a target car velocity V* is decided. Note
that the target car velocity V* is normally set to the
maintenance operation velocity or lower velocity, but may
be set to the rated velocity. When the car velocity V is
greater than the target car velocity V*, the current
command is continuously decreased to decelerate the car by
the brake torque (Step S106).
[0034]
In Step S107, whether or not the car velocity V is
less than the target car velocity V* is decided. When the
car velocity V is less than the target car velocity V*, the
current command is continuously increased to reduce the
brake torque to increase the velocity of the car.
[0035]
According to the above constitution, when the
controller transmits a command to change the braking force
to the brake from the state in which the passenger car is
stopped and the movement of the passenger car is detected
22
by the movement detection means, the controller controls
the braking force of the brake. By doing so, the braking
force of the brake is changed from the state in which the
brake is actuated to keep the passenger car, and the
passenger car starts to move when the braking force of the
brake becomes less than the torque generated from the
imbalance between the passenger car and the counterweight.
Moreover, by further controlling the braking force of the
brake after the passenger car starts to move, it is
possible to move the passenger car at low velocity and with
low vibration.
[0036]
In the present example, the model information
database (DB) shown in FIG. 2 is used to refer to the time
for stopping the increase of the current command value for
a certain period of time after the current is increased to
a certain value in order to wait for the change in the
magnetic flux. However, without providing the database, a
fixed value may be set according to the type of brake
having the slowest response. There are various types of
brakes, such as drum type, internal type, and shoe type,
and responsiveness differs according to the type of brake.
For this reason, when the car is moved by intermittently
releasing the brake with the technique disclosed in PTL 1,
the minimum time for opening and closing the brake differs
23
depending on the type of the brake. Thus, it is necessary
to separately adjust the control. When the fixed value is
set according to the type of brake having the slowest
response, the rescue operation can be performed by
releasing the brake without depending on the type of brake.
[0037]
Since the conventional rescue operation technique as
disclosed in PTL 1 moves to the car to the nearest floor by
intermittently releasing the brake, vibration occurs in the
passenger car by being applied the braking force
accompanying the intermittent release of the brake. In
particular, when the response speed of the mechanical
portion of the brake or the relay which shuts off the
voltage applied to the brake is slow, the velocityincreased
state caused by the imbalance between the
passenger car and the counterweight must be braked. Thus,
not only the vibration occurred in the passenger car
becomes large, but also the velocity of the passenger car
becomes difficult to be kept constant. Moreover, in the
elevator of long distance, the masses of the passenger car,
the counterweight, the sheave, and the rope increase. Thus,
the resonance point of the mechanical system is shifted to
the lower frequency side. Since the low frequency
vibration is difficult to attenuate in the mechanical
structure as compared with the radio frequency vibration,
24
it is known that the ride feeling experienced by the
passenger is deteriorated. In particular, in a case where
a voltage is applied to the brake at the time of start,
when a voltage for releasing the brake is directly applied,
not only the velocity increases by opening the brake, but
also an impact due to the acceleration change occurs at the
time of start. Furthermore, PTL 1 describes that linearly
changing the voltage at the time of start enables the start
without detecting the imbalance by a scale device of the
car. However, if the responsiveness of the coil used for
the brake is low, the voltage command reaches a value, at
which the brake can be sufficiently opened, when the brake
starts to open and the car moves. Thus, there is a
possibility of causing a sudden velocity increase of the
car. In particular, in the actuator, such as the brake,
constituted by the coil and the iron core, since the
magnetic permeability of the iron core is low, the
responsiveness of the change in the magnetic flux to the
change in the current is low, causing such a possibility.
[0038]
As described above, according to the present
invention, it has been shown that it is possible to provide
the elevator device and the rescue operation control method
for the elevator capable of preventing sudden acceleration
of the passenger car at the time of starting to move during
25
the brake release operation.
[0039]
Note that the present invention is not limited to the
above examples and includes various modification examples.
For example, the detailed description of the above examples
has been made so that the present invention can be easily
understood, and the present invention is not necessarily
limited to those including all the constitutions which have
been described. Moreover, part of the constitution of one
example can be replaced with the configurations of other
examples, and the constitutions of other examples can be
added to the constitution of one example. Furthermore,
addition, deletion and replacement of other constitutions
can be made to part of the constitution of each example.
Reference Signs List
[0040]
1 safety controller
2 elevator control unit
4 scale sensor
5 position sensor
7 means for detecting position, velocity and acceleration
of car
20 braking force control unit
26
WE CLAIM:
[Claim 1]
An elevator, comprising: a passenger car; a rope
whose one end is connected to the passenger car; a
counterweight connected to an other end of the rope; a
sheave around which the rope is wound; a solenoid coil
which weakens a braking force as a current supplied
increases; a brake device which brakes movement of the
passenger car by applying the braking force to the sheave;
a brake power supply which supplies the current to the
solenoid coil; a moving velocity detection means which
detects a moving velocity of the passenger car; and a
controller which controls the current supplied by the brake
power supply according to the moving velocity of the
passenger car detected by the moving velocity detection
means,
wherein the controller moves the passenger car by an
imbalance of weights between the passenger car and the
counterweight while the braking force is generated by the
brake device, by transmitting, to the brake power supply, a
command for increasing the current supplied to the solenoid
coil by a predetermined value every time a predetermined
time elapses when the passenger car is stopped and by
transmitting, to the brake power supply, a command for
stopping increasing the current supplied to the solenoid
27
coil when a velocity change of the passenger car is
detected by the moving velocity detection means.
[Claim 2]
The elevator according to claim 1, wherein
the controller transmits, to the brake power supply,
a command for continuously decreasing the current supplied
to the solenoid coil with time to stop the passenger car
when the passenger car is moving and a velocity of the
passenger car exceeding a specified velocity is detected by
the moving velocity detection means.
[Claim 3]
The elevator according to claim 1, wherein
the controller transmits, to the brake power supply,
a command for linearly decreasing the current supplied to
the solenoid coil with time to stop the passenger car when
the passenger car is moving and a velocity of the passenger
car exceeding a specified velocity is detected by the
moving velocity detection means.
[Claim 4]
The elevator according to any one of claims 1 to 3,
wherein
the predetermined time is longer than a time taking
from when the controller transmits, to the brake power
supply, the command for increasing the current supplied to
the solenoid coil until when a change in the braking force
28
of the brake device stops.
[Claim 5]
The elevator according to any one of claims 1 to 3,
wherein
the controller comprises a model information database
in which information on the predetermined time necessary
for each model is stored, and
the controller determines the predetermined time
according to the information recorded in the model
information database.
[Claim 6]
The elevator according to any one of claims 1 to 3,
wherein
the moving velocity detection means is an encoder
provided to a governor.
[Claim 7]
The elevator according to any one of claims 1 to 3,
wherein
the controller transmits, to the brake power supply,
a command for changing the current supplied to the solenoid
coil based on detection information of the moving velocity
detection means to move the passenger car to a floor where
a passenger can get off, when the passenger car is stopped
in emergency in a situation in which the passenger is in
the passenger car, and a rescue operation signal is
29
inputted into the controller.
[Claim 8]
The elevator according to claim 6, comprising
an external terminal which receives a status and an
operating state of the passenger car and transmits the
rescue operation signal to the controller,
wherein the controller receives the rescue operation
signal from the external terminal.
[Claim 9]
A rescue operation control method for an elevator
comprising: a passenger car; a rope whose one end is
connected to the passenger car; a counterweight connected
to an other end of the rope; a sheave around which the rope
is wound; a solenoid coil which weakens a braking force as
a current supplied increases; and a brake device which
brakes movement of the passenger car by applying the
braking force to the sheave, comprising:
increasing the current supplied to the solenoid coil
by a predetermined value every time a predetermined time
elapses when the passenger car is stopped in emergency and
a passenger is in the passenger car; and
moving the passenger car to a floor where the
passenger can get off by an imbalance of weights between
the passenger car and the counterweight while the braking
force is generated by the brake device, by stopping
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increasing the current supplied to the solenoid coil when a
velocity change of the passenger car is detected.