Technical Field
[0001] The present invention relates to an elevator and a control device for the same.
Background Art
[0002] Japanese Patent Application Laid-Open No.
2012-184043 (Patent Literature 1) is known as a reference document of the background art. This
patent publication discloses an elevator system which includes an elevator car and
a counterweight each liftably disposed in a hoistway and connected with each other
by a rope wound about a hoisting machine which rotates to move up and down the elevator
car. The elevator system further includes: a switch which is placed in on-state when
power supply to a hoist motor is cut off; and a dynamic brake circuit which connects
a resistor to a feed line via this switch so as to permit the consumption of an electromotive
force from the hoist motor. This patent publication further discloses a structure
where a rescue operation switch disposed at the elevator car is operated to release
a brake of the hoisting machine so as to permit the elevator car to be moved by means
of an uneven load balancing between the elevator car and the counterweight. During
this movement, a dynamic brake controller monitors the rotational speed of the hoisting
machine. When the rotational speed exceeds a predetermined value, the controller increases
the value of resistance by means of a resistance value changeover circuit.
Citation List
Patent Literature
[0003] PTL 1: Japanese Patent Application Laid-Open No.
2012-184043
Summary of Invention
Technical Problem
[0004] In the elevator system disclosed in Patent Literature 1, however, an adequate consideration
has not been given to a case where a braking torque obtained from a three-phase short
circuit in windings of the hoist motor is utilized for reducing a free running distance
at the time of emergency stop.
[0005] Specifically, in the light of the fact that the braking torque obtained from the
three-phase short circuit in the windings of the hoist motor is used for reducing
the free running distance at the emergency stop or for preventing the speed increase
during a rescue operation by means of brake release, it is desirable to configure
the hoist motor to be automatically short-circuited by a contact of contactor for
the former purpose and to be manually short-circuited by connection of a shorting
connector for the latter purpose.
[0006] When the braking torque is used for the latter purpose, a maintenance staff needs
to go to a control panel and manually connect the shorting connector. In a case where
the control panel is disposed in vicinity of the lowest part of the hoistway, the
maintenance staff can enter a pit and connect the shorting connector by directly changing
the connection of the connector in the control panel disposed in the pit. In contrast,
in a case where the control panel is disposed at the uppermost part of the hoistway,
it is difficult for the maintenance staff to access the control panel unless the elevator
car is near the highest floor. This indicates the need for extending a connection
portion of the connector to a hall indicator box. As the length of the wiring of the
connection portion of the connector increases, the three-phase short circuit is increased
in the resistance value. This results in a decreased effect of the braking torque
at the time of emergency stop.
[0007] An object of the invention is to facilitate an operation at the time of brake release
while maximizing the utilization of the braking torque by reducing the resistance
value of the circuit to be short-circuited at the time of emergency stop.
Solution to Problem
[0008] According to an aspect of the invention for achieving the above object, an elevator
control device which utilizes a braking torque for braking an elevator car, the braking
torque obtained from a three-phase short circuit in windings of a hoist motor connected
to a three-phase AC source via the control device,
the elevator control device including: a first short-circuit portion for generating
the braking torque at the time of emergency stop and a second short-circuit portion
for generating the braking torque during a rescue operation by means of brake release,
the first and second short-circuit portions provided as independent circuits, wherein
the second short-circuit portion includes a three-phase winding short terminal which
is for short-circuiting the windings of the hoist motor in three phases and disposed
in a hall indicator box.
Advantageous Effects of Invention
[0009] The invention facilitates the operation at the time of brake release while maximizing
the utilization of the braking torque by reducing the resistance value of the circuit
to be short-circuited at the time of emergency stop. Problems, configurations and
effects of the invention other than those described above will become apparent from
the following description of the embodiment thereof.
Brief Description of Drawings
[0010]
Figure 1 is a circuit diagram showing a schematic configuration of an elevator control
device according to one embodiment of the invention.
Figure 2 is a block diagram showing a specific configuration of a manual short-circuit
portion 7 shown in Figure 1.
Figure 3 is a circuit diagram showing a brake release circuit 11 shown in Figure 2.
Figure 4 is a diagram showing an example of an elevator equipped with the elevator
control device according to the invention.
Description of Embodiments
[0011] The embodiments of the invention will hereinbelow be described with reference to
the accompanying drawings.
<Example 1 >
[0012] Figure 4 is a diagram showing an example of an elevator system equipped with an elevator
control device according to the invention. Hereinafter, an elevator control device
3 (see Figure 1) will be simply referred to as "control device".
[0013] An elevator system 100 includes a hoistway 101 constructed in a building. In the
hoistway 101, an elevator car 103 and a counterweight 104 are connected with each
other by means of a rope 106 wound about a sheave 102 of a hoisting machine 105. The
elevator system 100 is configured to move up and down the elevator car and the counterweight
alternately by means of a hoist motor 1 rotatably driving the sheave 102 of the hoisting
machine 105.
[0014] The embodiment illustrates a structure where the hoisting machine 105 including the
hoist motor 1 and the sheave 102, and a control panel 8 accommodating the control
device 3 (see Figure 1) are disposed at the uppermost part of the inside of the hoistway
101. A hall H at the top floor is provided with a hall indicator box 9. The hall indicator
box 9 disposed at the top floor hall H is accessible from a floor F of the top floor
hall H.
[0015] Figure 1 is a circuit diagram showing a schematic configuration of the elevator control
device according to one embodiment of the invention.
[0016] In the following description, a case where a braking torque obtained from a three-phase
short circuit in windings of the hoist motor 1 is used for reducing the free running
distance at the emergency stop, namely an operation (braking torque) at "the time
of emergency stop" is distinguished from a case where the braking torque is used for
preventing the speed increase during a rescue operation by means of brake release,
namely an operation (braking torque) at the time of brake release.
[0017] In the elevator system 100 employing a permanent magnet synchronous motor, an electric
power from a three-phase AC source 2 is supplied to the hoist motor 1 via the control
device 3. Therefore, the control device 3 includes an inverter INV. The control device
3 further includes a controller for controllably switching a brake release operation
switch 13 and for controllably energizing a control transistor 19 for three-phase
short-circuit open contactor coil.
[0018] An automatic short-circuit portion 5 adapted to utilize the braking torque obtained
from the three-phase short circuit in the motor windings for reducing the free running
distance at the time of emergency stop includes a contact of contactor 4 which is
automatically closed. The automatic short-circuit portion 5 including this contact
of contactor 4 is disposed in the control panel 8 along with the control device 3.
[0019] In contrast, a manual short-circuit portion 7 adapted to utilize the braking torque
obtained from the three-phase short circuit in the motor windings for preventing the
speed increase during the rescue operation by means of brake release is short-circuited
by a shorting connector 6 manually connected. The manual short-circuit portion 7 is
disposed in the hall indicator box 9 provided at the hall H of the top floor.
[0020] A manual short terminal 7A of the manual short-circuit portion 7 is electrically
connected to the control device 3 accommodated in the control panel 8 by means of
a wiring 7B. That is, the manual short-circuit portion 7 essentially consists of the
manual short terminal 7A and the wiring 7B. Further, short terminals 10A, 10B are
disposed in the hall indicator box 9. The short terminals 10A, 10B are electrically
connected to a brake release circuit 11 disposed in the control panel 8 by means of
a wiring 10E. The details of the short terminals 10A, 10B and the brake release circuit
11 will be described hereinlater.
[0021] The short terminal 10A is a terminal to be short-circuited by a shorting connector
10C. The short terminal 10B is a terminal to be short-circuited by a shorting connector
10D. The shorting connector 10C, shorting connector 10D and shorting connector 6 are
integrally configured to permit one-step manual operation to cause short circuit at
the short terminal 10A, short terminal 10B and manual short-circuit portion 7.
[0022] The shorting connector 10C, shorting connector 10D and shorting connector 6 are accommodated
and stored in the hall indicator box 9.
[0023] Figure 2 is a block diagram showing a specific configuration of the manual short-circuit
portion 7 shown in Figure 1.
[0024] The manual short-circuit portion 7 includes the configuration in the control panel
8 and the configuration in the hall indicator box 9 which is responsible for indication
of registered car call floor(s) and car position. Configured in the hall indicator
box 9 are the manual short-circuit portion 7 and the short terminals 10A, 10B to be
connected by the shorting connector 6 and the shorting connectors 10A, 10B at the
time of brake release. The details of these components will be described hereinlater.
[0025] While a detailed description will be made hereinlater, the brake release circuit
11 including an exciting circuit is configured in the control panel 8. The exciting
circuit opens the contact of contactor 4 by exciting a three-phase short-circuit open
contactor coil 18 by means of a battery (brake release power source 12) when the shorting
connector 10C, 10D are connected to the short terminals 10A, 10B in the hall indicator
box 9.
[0026] In the case where the control panel 8 is disposed at the uppermost part of the hoistway
101, the access to the control panel 8 is unavailable unless the elevator car 103
is moved up to the vicinity of the top floor. If the manual short-circuit portion
7 is disposed in the hall indicator box 9 and the wiring 7A thereof is extended to
the hall indicator box 9 according to the traditional concept, the three-phase short
circuit will be unduly increased in resistance at the time of emergency stop. It is
desirable to ensure that the free running distance at emergency stop is short so that
a larger braking torque can be obtained at the time of emergency stop. As the three-phase
short circuit is increased in the resistance, however, the braking torque obtained
from the three-phase short circuit becomes less. Consequently, the effect of braking
torque is decreased.
[0027] According to the embodiment, therefore, short circuits (emergency-stop short circuit)
4, 5 for generating the braking torque by short-circuiting the windings of the hoist
motor 1 in three phases at the time of emergency stop are provided independently from
short circuits (brake-release short circuit) 6, 7 for generating the braking torque
by short-circuiting the windings of the hoist motor 1 in three phases at the time
of brake release. The emergency-stop short circuit essentially consists of the automatic
short-circuit portion 5 including the contact of contactor 4. The automatic short-circuit
portion 5 including the contact of contactor 4 is configured in the control panel
8 such as to be reduced in the wiring length for less wiring resistance.
[0028] In contrast, the brake-release short circuit essentially consists of the manual short-circuit
portion 7 and the shorting connector 6. The manual short terminal 7A disposed in the
hall indicator box 9 is for connection with the shorting connector 6 shown in Figure
1 at the time of brake release. Accordingly, the manual short-circuit portion 7 is
extended into the hall indicator box 9 so that the manual short terminal 7A is disposed
in the hall indicator box 9. Further, the short terminals 10A, 10B configured in the
brake release circuit 11 are electrically connected to the wiring 10E extended into
the hall indicator box 9 so that the terminals are disposed in the hall indicator
box 9.
[0029] As compared with the emergency-stop short circuits 4, 5, the brake-release short
circuits 6, 7 are less affected by the braking torque decrease due to the increase
in the wiring resistance. According to the embodiment, therefore, the brake-release
short circuits 6, 7 are independent from the emergency-stop short circuits 4, 5. When
the brake is released, the manual short terminal 7A is short-circuited by the shorting
connector 6 so that a simple operation in the hall indicator box 9 can generate the
braking torque by short-circuiting the windings of the hoist motor 1 in three phases.
Thus, the control device is improved in operability when the braking torque is utilized
at the time of brake release.
[0030] Further according to the embodiment where the emergency-stop short circuits 4, 5
are independent from the brake-release short circuits 6, 7, the emergency-stop short
circuits 4, 5 are not increased in resistance. Therefore, the utilization of braking
torque at emergency stop can be maximized.
[0031] Figure 3 is a circuit diagram showing the brake release circuit 11 shown in Figure
2.
[0032] The brake release circuit includes the brake release power source 12 such as battery
disposed in the control panel 8. The brake release power source 12 is connected with
a serial connection body including a brake release operation switch 13 and a brake
release contactor coil 14. The brake release power source 12 is further connected
with a serial connection body including a contact of brake release contactor 15 for
brake release contactor coil 14 and a brake coil 16.
[0033] When the brake release operation switch 13 is closed, the brake release contactor
coil 14 is excited to close the contact of brake release contactor 15 thereof. When
the contact of brake release contactor 15 is closed, the brake coil 15 is excited
to release an electromagnetic brake device. In contrast, a control power source for
normal operation 17 is connected with a serial connection body including the three-phase
short-circuit open contactor coil 18 and the control transistor 19 for three-phase
short-circuit open contactor coil.
[0034] The three-phase short-circuit open contactor coil 18 is excited to open the contact
of contactor 4 for opening the three-phase short circuit caused by the automatic short-circuit
portion 5. Moreover, the control transistor 19 for three-phase short-circuit open
contactor coil is turned ON to excite the three-phase short-circuit open contactor
coil 18.
[0035] The brake release circuit 11 of the embodiment features the short terminal 10A interposed
between the brake release operation switch 13 and the three-phase short-circuit open
contactor coil 18; and the short terminal 10B connected in parallel with the control
transistor 19 for three-phase short-circuit open contactor coil, which are added to
a common brake release circuit.
[0036] If the control power source for normal operation 17 is cut off, disabling the excitation
of the three-phase short-circuit open contactor coil 18, the short terminal 10A and
the short terminal 10B shown in Figure 3 are respectively short-circuited by the shorting
connectors 10C, 10D by connecting the short terminals 10A, 10B in the hall indicator
box 9 shown in Figure 2 with the shorting connectors 10C, 10D shown in Figure 1 and
Figure 2. Thus, the brake release contactor coil 14 and the three-phase short-circuit
open contactor coil 18 are connected to the brake release power source 12 to be excited,
respectively.
[0037] According to the embodiment, when the brake is released, the manual short-circuit
portion 7 is short-circuited by the shorting connector 6 while the short terminals
10A, 10B are short-circuited by the shorting connectors 10C, 10D and whereby the three-phase
short-circuit open contactor coil 18 is excited. The contact of contactor 4 is opened
by the excitation of the three-phase short-circuit open contactor coil 18. Therefore,
the embodiment can obtain the braking torque without mediation of the contact of contactor
4 so that load on the contact of contactor 4 can be reduced. This leads to an extended
service life of the contact of contactor 4.
[0038] As just described, the invention can provide the elevator control device which facilitates
the operation at the time of brake release while maximizing the utilization of the
braking torque by reducing the resistance value of the circuit to be short-circuited
at the time of emergency stop.
[0039] While the embodiment has been described by way of the configuration where the shorting
connector 10C, the shorting connector 10D and the shorting connector 6 are integrated,
the shorting connector 10C, the shorting connector 10D and the shorting connector
6 need not necessarily be formed in integral configuration. However, the integral
configuration of the shorting connector 10C, shorting connector 10D and shorting connector
6 permits the short-circuiting operation to be done in a short time. Further, a single
short-circuiting operation can accomplish the short-circuiting of all the three short-circuit
portions (short terminal 10A, short terminal 10B and manual short-circuit portion
7), thus preventing the short-circuiting operation from being left undone on any one
of the three short-circuit portions.
[0040] While the embodiment has be described on the assumption that the manual short terminal
7A and the short terminals 10A, 10B are disposed in the hall indicator box 9 provided
at the top floor hall H, the hall indicator box 9 accommodating these components need
not necessarily be provided at the hall H of the top floor. The manual short terminal
7A and the short terminals 10A, 10B may also be disposed in the hall indicator box
9 provided at a hall H of a floor lower than the top floor.
[0041] In particular, the wirings 7B of the brake-release short circuits 6, 7 can be increased
in length because the emergency-stop short circuits 4, 5 and the brake-release short
circuits 6, 7 are provided independently. This permits the manual short terminal 7A
and the short terminals 10A, 10B to be disposed in the hall indicator box 9 on a floor
away from the control panel 8 provided at the uppermost part of the hoistway 101.
In order to obtain the greater braking torque at the time of brake release, however,
the manual short terminal 7A and the short terminals 10A, 10B may preferably be disposed
in the hall indicator box 9 on the top floor in the elevator system where the control
panel 8 is provided at the upper most part of the hoistway 101.
[0042] The manual short terminal 7A and the short terminals 10A, 10B need not necessarily
be disposed in the hall indicator box 9. However, the manual short terminal 7A and
the short terminals 10A, 10B can be arranged in a simple configuration by accommodating
these components in the hall indicator box 9 as the existing structure.
[0043] While the embodiment has been described by way of the structure where the hoisting
machine 105 including the hoist motor 1 and the sheave 102, and the control panel
8 accommodating the control device 3 (see Figure 1) are disposed at the upper most
part of the hoistway 101, the hoisting machine 105 and the control panel 8 need not
necessarily be disposed at the upper most part of the hoistway 101. Further, the hoisting
machine 105 and the control panel 8 need not be located at the same place in the hoistway
101. At whatever place in the hoistway 101 the control panel 8 is disposed, the fact
remains that the operability is improved by the embodiment. However, the embodiment
is particularly effective because it is never easy to gain access to the control panel
8 in the case where the control panel 8 is disposed at the uppermost part of the hoistway
101.
[0044] It is noted that the invention is not limited to the foregoing embodiments but includes
a variety of changes and modifications. For example, the invention is applicable without
limitation to the brake release circuit 11 illustrated in Figure 3.
Reference Signs List
[0045]
1: hoist motor,
5: automatic short-circuit portion,
6: shorting connector,
7: manual short-circuit portion,
9: hall indicator box,
10A, 10B: short terminal,
11: brake release circuit,
14: brake release contactor coil,
18: three-phase short-circuit open contactor coil.
1. An elevator control device which utilizes a braking torque for braking an elevator
car, the braking torque obtained from a three-phase short circuit in windings of a
hoist motor connected to a three-phase AC source via the control device,
the elevator control device comprising: a first short-circuit portion for generating
the braking torque at the time of emergency stop and a second short-circuit portion
for generating the braking torque at the time of rescue operation by means of brake
release, the first and second short-circuit portions provided as independent circuits,
wherein
the second short-circuit portion includes a three-phase winding short terminal which
is for short-circuiting the windings of the hoist motor in three phases and disposed
in a hall indicator box.
2. The elevator control device according to Claim 1, wherein
the first short-circuit portion is an automatic short-circuit portion which is disposed
in a control panel accommodating the elevator control device and is automatically
activated at the time of emergency stop, and
the second short-circuit portion is a manual short-circuit portion for manually short-circuiting
the three-phase winding short terminal by using a shorting connector.
3. The elevator control device according to Claim 2, further comprising: a contact of
contactor which is disposed at the automatic short-circuit portion for short-circuiting
the windings of the hoist motor in three phases; and a three-phase short-circuit open
contactor coil which is excited to open the contact of contactor, wherein
a three-phase short-circuit open short terminal for exciting the three-phase short-circuit
open contactor coil by connecting the contactor coil to a power source is disposed
in the hall indicator box.
4. The elevator control device according to Claim 3, wherein
during the rescue operation by means of brake release, the three-phase short-circuit
induced by the first short-circuit portion is opened by short-circuiting the three-phase
short-circuit open short terminal with a shorting connector, while the braking torque
is generated by the three-phase short-circuit induced by the second short-circuit
portion.
5. An elevator system which includes in a hoistway: a hoisting machine including a hoist
motor and a sheave; a rope wound about the sheave; and an elevator car and a counter
weight connected with each other by means of the rope, comprising the elevator control
device according to any one of Claims 1 to 4.
6. The elevator system according to Claim 5, wherein
a control panel accommodating the elevator control device is disposed at the uppermost
part of the hoistway.