EP2457861B1

EP2457861B1 - Control device for elevator

Info

Publication number: EP2457861B1
Application number: EP09847541.1A
Authority: EP
Inventors: Masunori Shibata
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2009-07-21
Filing date: 2009-07-21
Publication date: 2016-08-17
Anticipated expiration: 2029-07-21
Also published as: EP2457861A1; KR20120014003A; EP2457861A4; CN102471020B; JPWO2011010356A1; CN102471020A; JP5265009B2; WO2011010356A1

Description

Technical Field

The present invention relates to a control device for an elevator, for performing an operation offering high convenience even in case of occurrence of an abnormality in a brake.

Background Art

As a first conventional control device for an elevator, there is a control device which includes a brake, a brake non-operation detecting circuit, an operation failure detecting circuit, and an operation circuit. When a failure in a brake operation is detected, a car is moved according to a load (for example, see Patent Literature 1). Specifically, the brake is operated in response to a braking command to function to constrain a car-driving electric motor. The brake non-operation detecting circuit detects that the brake is not in operation. The operation failure detecting circuit detects a state in which the brake non-operation detecting circuit is in operation (specifically, the brake is not in operation) although the braking command is issued. The operation circuit moves the car to a bottom floor when the load is heavy and to a top floor when the load is light, depending on a detection signal of the operation failure detecting circuit.
As a second conventional control device for an elevator, there is a control device which stops an operation of the elevator when the occurrence of a slip of an electromagnetic brake is detected (for example, see Patent Literature 2). Specifically, when a car stops at a floor, a braking command is output from the control device. With the output of the braking command, contacts are opened to de-energize a brake coil. As a result, the electromagnetic brake starts a braking operation. When a brake switch detects that a permanent-magnet synchronous electric motor is braked by the electromagnetic brake, a power converter interrupts power supplied to the electric motor. Then, the number of pulse signals output from a pulse generator connected to the electric motor within a predetermined time is counted. When a value of the number of the pulse signals exceeds a predetermined slip-detection value which is previously defined, the occurrence of the slip of the electromagnetic brake is detected. Then, after the detection of an abnormality in the electromagnetic brake, an operation of the elevator is stopped.
Further, as a third conventional control device for an elevator, there is a control device which prevents a passenger(s) from being endangered when sliding movement is detected (for example, see Patent Literature 3). Specifically, control means includes slide detection means for detecting sliding movement of a car based on a running speed when a power command is interrupted and a braking command is output. In this manner, in the case where the sliding movement is detected based on an abnormal value of the running speed when the car lands to be stopped, the passenger(s) is (are) prevented from being endangered.

Citation List

Patent Literature

[PTL 1] JP 1316612 B2
JP2008207898 shows a state of the art control device according to the preamble of claim 1.

Summary of Invention

Technical Problem

However, the conventional technologies have the following problems.
For the first conventional control device for the elevator, which is described in Patent Literature 1, the following example is described. The non-operating state of the brake is detected by the brake non-operation detecting circuit. After the detection of the abnormality, a door-closing command is output. Then, after running to a terminal landing is performed, activation is disabled. Specifically, in the case where the abnormality of the brake is detected, the first conventional control device for the elevator disables the activation after closing the door and then causing the elevator to run to a predetermined floor. Therefore, there is a fear in that a passenger(s) may be trapped in the car if there are any passenger(s).
In an elevator device including at least two electromagnetic brakes, however, it is considered that the car can be kept stationary with the normally operating electromagnetic brake alone even if at least one of the electromagnetic brakes is abnormal. In such a case, it is desirable that the activation of the elevator be disabled after the passenger(s) deboards(deboard).
In the case of the second conventional control device for the elevator, which is described in Patent Literature 2, it is considered that the case where a brake switch for detecting an operating state of the brake does not detect a closed state of the brake may happen even if the control device includes two or more electromagnetic brakes. In such a case, the passenger(s) results(result) in being trapped in the car even with the second conventional control device for the elevator, which offers low convenience.
Further, the third conventional control device for the elevator, which is described in Patent Literature 3, detects the slip of the brake by using a signal of a rotation detector. In such a case, the loss of a brake torque can be reliably detected. However, an operating state of the brake switch which directly detects the operating state of the brake is not taken into consideration.
The present invention has been made to solve the problems described above, and has an object to provide an elevator device with high convenience including two or more electromagnetic brakes, which prevents a passenger(s) from being trapped in a car as much as possible.

Solution to Problems

According to the present invention, there is provided a control device for an elevator, including: a plurality of electromagnetic brakes provided independently from a hoisting motor, each of the plurality of electromagnetic brakes having an independent brake coil and an independent actuation mechanism for stationary retention; a plurality of brake switches for individually detecting a respective open state and a respective closed state of the plurality of electromagnetic brakes; a door-opening zone detector for detecting a door-opening zone corresponding to a range in which a door of a car can be opened and closed; and a control section for outputting brake release commands and brake close commands for turning ON and OFF a current through the respective brake coils of the plurality of electromagnetic brakes to perform opening and closing control for the plurality of electromagnetic brakes and for outputting a door-opening command and a door-closing command based on results of detection of the door-opening zone detector to perform opening and closing control for the door, in which, in a case where a state in which a closed state of at least one of the plurality of brake switches cannot be detected occurs even though the brake close commands are output after it is detected that the car is present in the door-opening zone by the door-opening zone detector while the door-closing command is currently output, when it is detected that at least a predetermined number of the plurality of brake switches is in the closed state, the control device outputs the door-closing command after outputting the door-opening command for a predetermined time and then stops service of the elevator, and when it is not detected that at least the predetermined number of the plurality of brake switches is in the closed state, the control device immediately stops the service of the elevator.

Advantageous Effects of Invention

According to the control device for the elevator of the present invention, even if the state in which the closed state of at least one of the plurality of brake switches cannot be detected occurs, a door-opening operation is enabled before service for the passenger(s) is stopped when it is determined that a sufficient number of electromagnetic brakes to keep the car stationary is (are) in operation. As a result, in the elevator device including the two or more electromagnetic brakes, the highly convenient control device for the elevator, which prevents the passenger(s) from being trapped in the car as much as possible, can be provided.

Brief Description of Drawings

[FIG. 1] A diagram illustrating an overall configuration of a control device for an elevator according to Embodiment 1 of the present invention.
[FIG. 2] A flowchart illustrating an operation of the control device for the elevator according to Embodiment 1 of the present invention.
[FIG. 3] A diagram illustrating an overall configuration of a control device for an elevator according to Embodiment 2 of the present invention.
[FIG. 4] A flowchart illustrating an operation of the control device for the elevator according to Embodiment 2 of the present invention.

Description of Embodiments

Hereinafter, a control device for an elevator according to preferred embodiments of the present invention is described referring to the drawings. For simplifying the description, a control device for an elevator, which includes two electromagnetic brakes, is described below as an example of a plurality of independent electromagnetic brakes.

Embodiment 1

FIG. 1 is a diagram illustrating an overall configuration of a control device for an elevator according to Embodiment 1 of the present invention. In FIG. 1, a car 1 is provided in a hoistway of an elevator. The car 1 is controlled so as to stop at each floor 2. A door control section 3 for controlling opening/closing of a car door (not shown) is provided to the car 1. Moreover, a door-opening zone detector 4 for detecting a door-opening zone corresponding to the range in which the car door can be opened/closed is provided to the car 1. Detection plates 5 are provided in the hoistway so as to face the door-opening zone detector 4.
In a machine room present above the hoistway, a hoisting machine including a hoisting motor 6 is provided. A main rope 8 is looped around a driving sheave 7 provided to a shaft of the hoisting motor 6. The car 1 and a counterweight 9 are respectively connected to two ends of the main rope 8. A pulse generator 10 is mounted to the shaft of the hoisting motor 6. A first electromagnetic brake 11 and a second electromagnetic brake 13, which are independent of each other, are provided to the hoisting motor 6.
The first electromagnetic brake 11 includes a brake shoe 11a for braking the hoisting motor 6 by a force of a spring (not shown) and a brake coil 11b for independently attracting the brake shoe 11a to release braking when being biased, whereas the second electromagnetic brake 13 includes a brake shoe 13a for braking the hoisting motor 6 by a force of a spring (not shown) and a brake coil 13b for independently attracting the brake shoe 13a to release braking when being biased. Moreover, a first brake switch 12 for independently detecting an operation of the brake shoe 11a and a second brake switch 14 for independently detecting an operation of the brake shoe 13a are provided.
The brake coil 11b is connected to a DC power source 17 through an intermediation of normally- open contacts 15a and 15b of an electromagnetic contactor (not shown), whereas the brake coil 13b is connected to the DC power source 17 through an intermediation of normally- open contacts 16a and 16b of an electromagnetic contactor (not shown). In a state in which brake release commands Bs1 and Bs2 are output, the normally- open contacts 15a, 15b, 16a, and 16b are closed because the electromagnetic contactors are placed in an excited state. As a result, the brake coils 11b and 13b are placed in an excited state to bring the brake into an OFF state. On the other hand, in a state in which the brake release commands Bs1 and Bs2 are not output (specifically, are interrupted), the normally- open contacts 15a, 15b, 16a, and 16b are opened because the electromagnetic contactors are placed in a non-excited state. As a result, the brake coils 11b and 13b are placed in a non-excited state to bring the brake into an ON state.
A control device 20 including a brake control section for controlling entirely the first electromagnetic brake 11 and the second electromagnetic brake 13 is configured by a microcomputer. The microcomputer includes a CPU 21, a ROM 22, a RAM 23, an input port 24, and an output port 25, which are connected to each other through a bus 26.
The input port 24 is connected to the pulse generator 10, the brake switches 12 and 14, and the door-opening zone detector 4. In this manner, the CPU 21 can detect various states of the elevator. More specifically, for detecting a running state of the car, an output pulse P is input from the pulse generator 10 to the input port 24. For detecting a braked state, a first brake operation signal Bd1 is input from the first brake switch 12 to the input port 24, whereas a second brake operation signal Bd2 is input from the second brake switch 14 to the input port 24. Further, for detecting whether or not the car door is an openable/closable state, a floor detection signal Zs is input from the door-opening zone detector 4 to the input port 24.
On the other hand, the output port 25 is connected to the electromagnetic contactor including the contact 15a and 15b and the electromagnetic contactor including the contacts 16a and 16b, the door control section 3, and a power converter 27. More specifically, for ON/OFF control of the brake, when the brake is to be turned OFF, the first brake release command Bs1 and the second brake release command Bs2 are output to the electromagnetic contactors. On the other hand, for turning the brake ON, the first brake release command Bs1 and the second brake release command Bs2 are interrupted without being output to the electromagnetic contactors.
For opening/closing control of the door, a door-closing command Dcs and a door-opening command Dos are output to the door control section 3. Further, for speed control of the car, a torque command Ts is output to the power converter 27. The power converter 27 is connected to the hoisting motor 6.
Next, an operation series of the control device for the elevator according to Embodiment 1 of the present invention is described. First, an overall operation is described. The control device 20 including the brake control section generates the torque command Ts so that three-phase AC power Pm is supplied from the power converter 27 to the hoisting motor 6 to drive the hoisting motor 6. Then, the control device 20 performs control so that a rotation speed of the hoisting motor 6 becomes equal to a speed command signal to perform a raising/lowering operation of the car 1 although the detailed description thereof is herein omitted.
At this time, the brake release commands Bs1 and Bs2 are output. Therefore, the contacts 15a, 15b, 16a, and 16b are in the closed state. Thus, the brake coils 11b and 13b are biased to release the brake shoes 11a and 13a, respectively, to release the hoisting motor 6.
In this manner, the car 1 starts running and then lands at the floor at which a call is made. Then, when the door-opening zone detector 4 faces a corresponding one of the detection plates 5, the floor detection signal Zs is generated from the door-opening zone detector 4 so as to be input to the control device 20. By the input, the control device 20 determines that the car 1 stops within a door-opening zone of the target floor and interrupts the torque command Ts which is output to the power converter device 27. At the same time, the brake release command Bs1 to the first electromagnetic brake 11 and the brake release command Bs2 to the second electromagnetic brake 13 are interrupted. As a result, the contacts 15a, 15b, 16a, and 16b are opened. Therefore, the hoisting motor 6 is braked by the brake shoes 11a and 13a.
A specific operation performed when the elevator performs normal running to land at the floor 2 is described using a flowchart. FIG. 2 is a flowchart illustrating the operation of the control device for the elevator according to Embodiment 1 of the present invention.
In Step S1, the car 1 lands at the floor 2. Then, in Step S2, the control device 20 interrupts the brake release commands Bs for applying the brake. As a result, as described above, the hoisting motor 6 is brought into the braked state. Next, in Step S3, the control device 20 determines whether or not the brake switches 12 and 14 operate to output the brake operation signals Bd, specifically, the electromagnetic brakes 11 and 13 are brought into the braking state.
When it is determined that the brake switches 12 and 14 are in operation, the control device 20 turns the torque command Ts OFF to interrupt the supply of the three-phase AD power Pm from the power converter 27 in Step S4. On the other hand, when it is determined that the brake switches 12 and 14 are not in operation in Step S3, the operation proceeds to Step S4 after the control device 20 waits for the elapse of a predetermined time in Step S5.
Next, in Step S6, the control device 20 determines whether or not the brake switches 12 and 14 are both in operation. Then, when it is determined that the brake switches 12 and 14 are both in operation, the control device 20 determines that the electromagnetic brakes 11 and 13 normally operate. Then, in Step S7, if the door-opening zone detector 4 outputs the floor detection signal Zs, the door-opening command Dos is output to open the door.
On the other hand, when it is determined that one or more of the brake switches 12 and 14 is (are) not in operation (specifically, a state in which the brake switches 12 and 14 are not both in operation) in Step S6, the control device 20 determines whether or not a predetermined number of the brake switches 12 and 14 is (are) in operation in Step S8. Here, as the predetermined number, a minimum number of the brake switches, which allows(allow) the electromagnetic brake(s) to generate a torque enabling the retention of a load larger than an operation level (110% load) of an elevator overload detector and enabling the retention of a load larger than that of the car 1 when no load is present in the car 1, is set. In Embodiment 1, design is made so that the operation level of the overload detector can be maintained with a single electromagnetic brake. Therefore, in this case, the predetermined number is 1.
When it is determined that the predetermined number of brake switches is (are) in operation (specifically, only one of the brake switches 12 and 14 is in operation in the case of Embodiment 1) as a result of the determination in Step S8, the control device 20 determines that at least stationary retention of the car is possible. Then, in Step S9, when the door-opening zone detector 4 outputs the floor detection signal Zs, the control device 20 outputs the door-opening command Dos to open the door. Thereafter, in Step S10, the activation of the elevator is disabled.
When it is determined that the number of brake switches which is (are) in operation is less than the predetermined number (specifically, neither the brake switches 12 nor 14 is in operation in the case of Embodiment 1) as a result of the determination in Step S8, the control device 20 determines that the stationary retention of the car is impossible. Therefore, the control device 20 disables the activation of the elevator in Step S10 without passing through Step S9.
By the operation series described above, even if the control device 20 determines that one or more brake switch(es) is (are) not in operation after the braking command is output (specifically, the brake release commands are interrupted) while the car 1 is in a stopped state, the door is opened to allow a passenger(s) to deboard and then the service is stopped when a sufficient number of electromagnetic brake(s) to keep the car stationary is (are) in operation.
On the other hand, when it is determined that one or more brake switch(es) is (are) not in operation and the sufficient number of electromagnetic brake(s) to keep the car stationary is (are) not in operation, the control device 20 stops the service for the passenger(s) without opening the door. As a result, the highly convenient control device for the elevator, which prevents the passenger(s) from being trapped in the car as much as possible, can be provided.
As described above, according to Embodiment 1, even if one or more brake switch(es) is (are) not in operation, the control device can perform the door-opening operation before stopping the service for the passenger(s) when the control device determines that the sufficient number of electromagnetic brake(s) to keep the car stationary is (are) in operation. As a result, a possibility that the passenger(s) gets(get) stuck in the car can be reduced as much as possible, thereby realizing the highly convenient control device for the elevator.

Embodiment 2

In Embodiment 2, a case where a weighing device 28 for detecting the load in the car 1 is additionally provided to the configuration illustrated in FIG. 1, which is described above in Embodiment 1, so that the number of electromagnetic brakes which can keep the car stationary is dynamically determined according to a load amount Wg is described.
FIG. 3 is a diagram illustrating an overall configuration of a control device for an elevator according to Embodiment 2 of the present invention. The elevator device according to Embodiment 2 further includes the weighing device 28 for detecting the load in the car 1 in addition to the configuration illustrated in FIG. 1, which is described in Embodiment 1 described above. The remaining configuration is the same as that illustrated in FIG. 1 according to Embodiment 1 described above and is described below mainly for the additionally provided weighing device 28 by using the flowchart. The weighing device 28 is connected to the input port 24. In this manner, the CPU 21 can read the load amount Wg detected by the weighing device 28.
FIG. 4 is a flowchart illustrating an operation of the control device for the elevator according to Embodiment 2 of the present invention. In comparison with the flowchart of FIG. 2 referred to in Embodiment 1 described above, Steps S21 to S23 are added and Step S24 is used in place of Step S8 in the flowchart of FIG. 4 of Embodiment 2. In the other steps, the same operations as those performed in the steps of FIG. 2 are performed.
When a call is made at one of the floors, the control device 20 outputs the door-closing command Dcs to perform the door-closing operation in Step S21. In Step S22, the load in the car 1 is obtained from the weighing device 28. Thereafter, in Step S23, the elevator is controlled to run toward the target floor.
Next, in Step S1, the car 1 lands at the floor 2. Then, in Step S2, the control device 20 interrupts the brake release commands Bs for applying the brake. As a result, as described above, the hoisting motor 6 is brought into the braked state. Next, in Step S3, the control device 20 determines whether or not the brake switches 12 and 14 operate to output the brake operation signals Bd, specifically, the electromagnetic brakes 11 and 13 are brought into the braking state.
When it is determined that the brake switches 12 and 14 are in operation, the control device 20 turns the torque command Ts OFF to interrupt the supply of the three-phase AD power Pm from the power converter 27 in Step S4. On the other hand, when it is determined that the brake switches 12 and 14 are not in operation in Step S3, the operation proceeds to Step S4 after the control device 20 waits for the elapse of the predetermined time in Step S5.
Next, in Step S6, the control device 20 determines whether or not the brake switches 12 and 14 are both in operation. Then, when it is determined that the brake switches 12 and 14 are both in operation, the control device 20 determines that the electromagnetic brakes 11 and 13 normally operate. Then, in Step S7, if the door-opening zone detector 4 outputs the floor detection signal Zs, the door-opening command Dos is output to open the door.
On the other hand, when it is determined that one or more of the brake switches 12 and 14 is (are) not in operation (specifically, a state in which the brake switches 12 and 14 are not both in operation) in Step S6, the control device 20 determines whether or not a predetermined number of the brake switches 12 and 14 is (are) in operation in Step S24. Here, as the predetermined number, a minimum number of the brake switches, which allows(allow) the electromagnetic brake(s) to generate a torque enabling the retention of a load larger than both a load retained with the torque enabling the retention of the load in the car 1, which is obtained in the previous Step S22, and a load retained with the torque enabling the retention of the car 1 when no load is present in the car 1, is set. Specifically, in Embodiment 2, the predetermined number is dynamically specified according to the load in the car 1, which is measured by the weighting device 28.
When it is determined that the predetermined number of brake switches is (are) in operation as a result of the determination in Step S24, the control device 20 determines that at least stationary retention of the car is possible. Then, in Step S9, when the door-opening zone detector 4 outputs the floor detection signal Zs, the control device 20 outputs the door-opening command Dos to open the door. Thereafter, in Step S10, the activation of the elevator is disabled.
When it is determined that the number of brake switches which is (are) not in operation is less than the predetermined number as a result of the determination in Step S24, the control device 20 determines that the stationary retention of the car is impossible. Therefore, the control device 20 disables the activation of the elevator in Step S10 without passing through Step S9.
By the processing series described above, even if it is determined one or more brake switch(es) is (are) not in operation after outputting the braking command (specifically, interrupting the brake release commands) while the car 1 is in the stopped state, the control device 20 opens the door to allow the passenger(s) to deboard and then stops the service when determining that the minimum brake torque capable of keeping the car 1 stationary is ensured both in the current state with the passenger(s) present in the car and in the no-load state after the deboarding of the passenger(s).
On the other hand, when it is determined that one or more brake switch(es) is (are) not in operation and the sufficient number of electromagnetic brake(s) to keep the car stationary is (are) not in operation both in the current state with the passenger(s) present in the car and in the no-load state after the deboarding of the passenger(s), the control device 20 stops the service for the passenger(s) without opening the door. As a result, the highly convenient control device for the elevator, which prevents the passenger(s) from being trapped in the car as much as possible, can be provided.
As described above, according to Embodiment 2, even if one or more brake switch(es) is (are) not in operation, the control device can perform the door-opening operation before stopping the service for the passenger(s) according to the load in the car when it is determined that the sufficient number of electromagnetic brakes to keep the car stationary is (are) in operation. As a result, appropriate control according to the load present in the car can be performed. As a result, the fear that the passenger(s) gets(get) stuck in the car can be further reduced as compared with Embodiment 1 described above. Accordingly, the highly convenient control device for the elevator can be realized.

Claims

A control device for an elevator, comprising:
a plurality of electromagnetic brakes (11) provided independently from a hoisting motor, each of the plurality of electromagnetic brakes (11) having an independent brake coil and an independent actuation mechanism for stationary retention;

a plurality of brake switches (12) for individually detecting a respective open state and a respective closed state of the plurality of electromagnetic brakes (11);

a door-opening zone detector (4) for detecting a door-opening zone corresponding to a range in which a door of a car can be opened and closed; and

a control section (20) for outputting and interrupting brake release commands for turning ON and OFF a current through the respective brake coils of the plurality of electromagnetic brakes (11) to perform opening and closing control for the plurality of electromagnetic brakes (11) and for outputting a door-opening command and a door-closing command based on results of detection of the door-opening zone detector (4) to perform opening and closing control for the door,
characterised in that,
in a case where a state in which a closed state of at least one of the plurality of brake switches (12) cannot be detected occurs even though the brake release commands are interrupted after it is detected that the car is present in the door-opening zone by the door-opening zone detector (4) while the door-closing command is currently output, when it is detected that at least a predetermined number of the plurality of brake switches (12) is in the closed state, the control section (20) outputs the door-closing command after outputting the door-opening command for a predetermined time and then stops service of the elevator, and when it is not detected that at least the predetermined number of the plurality of brake switches (12) is in the closed state, the control section (20) immediately stops the service of the elevator.
A control device for an elevator according to claim 1, wherein the control section (20) performs the opening and closing control for the plurality of electromagnetic brakes (11) and performs the opening and closing control for the door, using, as the predetermined number, a minimum number of the plurality of electromagnetic brakes (11) required for generating a torque which allows a load larger than an operation level of an elevator overload detector to be retained and allows the car in a no-load state to be retained.
A control device for an elevator according to claim 1, further comprising a weighing device (28) for detecting a load capacity in the car of the elevator,
wherein the control section (20) performs the opening and closing control for the plurality of electromagnetic brakes (11) and performs the opening and closing control for the door, using, as the predetermined number, a minimum number of the plurality of electromagnetic brakes (11) required for generating a torque which allows the load capacity detected by the weighing device to be retained and allows the car in a no-load state to be retained.