ELEVATOR DEVICE

Abstract

 In an elevator apparatus, a travel controller controls a travel of a car. The travel controller also generates an operation command signal for operating a brake device. A brake controller controls the brake device in response to the operation command signal from the travel controller. When a failure of the brake controller is detected, the control performed by the brake controller is invalidated so that the brake device is directly operated in response to the operation command signal.

Description

Technical Field

[0001] The present invention relates to an elevator apparatus including a brake controller capable of controlling a braking force of a brake device.

Background Art

[0002] In a conventional elevator apparatus, when a failure is detected by a self-diagnosis of a brake controller, a contactor of a brake coil is immediately de-energized to bring a car to an emergency stop (for example, see Patent Literature 1).

Citation List

Patent Literature

[0003] 

Patent Literature 1: WO 2007/060733 A1

Summary of Invention

Technical Problem

[0004] In the conventional elevator apparatus described above, the car is brought to the emergency stop when the failure of the brake controller is detected. Therefore, there is a fear in that a passenger(s) gets(get) stuck in the car. Therefore, there is a problem that a maintenance personnel is required to perform a rescue operation each time the passenger(s) gets (get) stuck.

[0005] The present invention has been made to solve the problem described above, and therefore has an object to provide an elevator apparatus which enables a brake device to perform a braking operation and a brake-release operation even in case of a failure of a brake controller so that a passenger is prevented from getting stuck in a car.

Solution to Problem

[0006] An elevator apparatus according to the present invention includes: a car; a brake device for braking running of the car; a travel controller for generating an operation command signal for operating the brake device to control a travel of the car; and a brake controller for controlling a braking force of the brake device in response to the operation command signal, in which when a failure of the brake controller is detected, the control performed by the brake controller is invalidated so that the brake device is directly operated in response to the operation command signal.

Advantageous Effects of Invention

[0007] The elevator apparatus according to the present invention uses the operation command signal from the travel controller to operate the brake deice when the failure of the brake controller is detected. Therefore, even when the failure occurs in the brake controller, the brake device can perform a braking operation and a brake-release operation so that a passenger is prevented from getting stuck in the car.

Brief Description of Drawings

[0008] 

Figure 1 is a configuration diagram illustrating an elevator apparatus according to Embodiment 1 of the present invention.

Figure 2 is a block diagram illustrating a principal part of the elevator apparatus illustrated in Figure 1.

Figure 3 is a flowchart illustrating a deceleration control operation of a brake controller illustrated in Figure 1.

Figure 4 is a flowchart illustrating an abnormality diagnosis operation of the brake controller illustrated in Figure 1.

Figure 5 is a graph showing a relation between a first threshold value and a second threshold value of a car deceleration, which are set for the brake controller illustrated in Figure 1, and a car position.

Figure 6 is a block diagram illustrating a signal switching section illustrated in Figure 2.

Figure 7 is a graph illustrating an example of a brake current command signal generated by an output control logic circuit section illustrated in Figure 6.

Description of Embodiment

[0009] Hereinafter, an embodiment of the present invention is described referring to the drawings.

Embodiment 1

[0010] Figure 1 is a configuration diagram illustrating an elevator apparatus according to Embodiment 1 of the present invention. In the figure, a car and a counterweight 2 are suspended in a hoistway by a main rope 3 corresponding to suspension means, and are raised and lowered in the hoistway by a driving force of a hoisting machine 4.

[0011] The hoisting machine 4 includes a drive sheave 5 around which the main rope 3 is looped, a hoisting-machine motor 6 for rotating the drive sheave 5, and a brake device 7 for braking the rotation of the drive sheave 5. The brake device 7 includes a brake drum (brake wheel) 8 connected coaxially to the drive sheave 5, a brake shoe 9 to be brought into contact with and separated away from the brake drum, a brake spring for pressing the brake shoe 9 against the brake drum 8 to apply a braking force thereto, and an electromagnetic magnet for separating the brake shoe 9 away from the brake drum 8 against the brake spring to release the braking force. Specifically, an electromagnetic brake is used as the brake device 7.

[0012] The hoisting-machine motor 6 is provided with a hoisting-machine encoder 10 corresponding to a first speed detection section for generating a signal according to a rotation speed of a rotary shaft thereof, specifically, a rotation speed of the drive sheave 5. The hoisting-machine encoder 10 generates two-system detection signals independent of each other.

[0013] In a part of the hoistway in the vicinity of a top terminal landing, an upper hoistway switch 11 is provided. In a part of the hoistway in the vicinity of a bottom terminal landing, a lower hoistway switch 12 is provided. The hoistway switches 11 and 12 are used as position correction switches for detecting an absolute position of the car 1 to modify car position information. An operating cam 13 for operating the hoistway switches 11 and 12 are mounted to the car 1.

[0014] On a bottom (in a pit) of the hoistway, a car buffer 14 and a counterweight buffer 15 are provided. The car buffer 14 is placed immediately below the car 1. The counterweight buffer 15 is placed immediately below the counterweight 2.

[0015]  In an upper part of the hoistway, a governor sheave 16 is provided. In a lower part of the hoistway, a tension sheave 17 is provided. A governor rope (overspeed detection rope) 18 is looped around the governor sheave 16 and the tension sheave 17. Both ends of the governor rope 18 are connected to the car 1. The governor rope 18 is circulated with the raising and lowering of the car 1. As a result, the governor sheave 16 and the tension sheave 17 are rotated at a speed according to a running speed of the car 1.

[0016] A governor encoder 19 corresponding to a second speed detection section for generating a signal according to a rotation speed of the governor sheave 16, specifically, a speed of the car 1 is provided to the governor sheave 16. The governor encoder 19 generates two-system detection signals independent of each other.

[0017] The brake device 7 is controlled by a brake controller 20. Signals from the hoisting-machine encoder 10, the hoistway switches 11 and 12, and the governor encoder 19 are input to the brake controller 20. A signal according to a current flowing through the electromagnetic magnet of the brake device 7 is also input to the brake controller 20.

[0018] The brake controller 20 controls the braking force of the brake device 7 in response to the signal from the hoisting-machine encoder 10 and the current signal of the electromagnetic magnet (brake current value). The brake controller 20 also controls the braking force of the brake device 7 so as to prevent a deceleration of the car 1 from being excessively large when the car 1 is to be brought to an emergency stop.

[0019] A travel of the car 1 is controlled by a travel controller 21. Specifically, the travel controller 21 controls the hoisting-machine motor 6 and the brake controller 20. The travel controller 21 includes a microcomputer for travel control. The brake controller 20 includes a microcomputer for brake control.

[0020] The brake controller 20 includes a duplexed computation section, specifically, a first computation section and a second computation section, and is capable of detecting its own failure by comparing the results of computations.

[0021] Figure 2 is a block diagram illustrating a principal part of the elevator apparatus illustrated in Figure 1. A brake coil (electromagnetic coil) 22 is provided to the electromagnetic magnet of the brake device 7. By allowing a current to flow through the brake coil 22, the electromagnetic magnet is excited to generate an electromagnetic force for releasing the braking force of the brake device 7. As a result, the brake shoe 9 is separated away from the brake drum 8. The de-energization of the brake coil 22 de-excites the electromagnetic magnet to press the brake shoe 9 against the brake drum 8 by the spring force of the brake spring. Further, the control of a value of the current flowing through the brake coil 22 enables the control of the braking force of the brake device 7.

[0022] The brake coil 22 is connected to a power-supply device 24 through an intermediation of a brake coil contactor 23. The brake coil contactor 23 is connected to the power-supply device 24 through an intermediation of a safety circuit switch group 25. The safety circuit switch group 25 includes a plurality of safety switches connected in series. When at least one of the safety switches is opened, the brake coil contactor 23 is de-energized to de-energize the brake coil 22.

[0023] The travel controller 21 includes a brake operation command generating section 21a for generating an operation command signal for operating the brake device 7. The operation command signals include a contactor command signal Sc1 for commanding the energization/de-energization of the brake coil contactor 23 and a brake command signal Sb1 for commanding the energization/de-energization of the brake coil 22 (pull-in/release of the brake shoe 9).

[0024] A signal switching section 26 is provided between the travel controller 21 and the brake controller 20, and the brake device 7. The signal switching section 26 is connected to the travel controller 21 and the brake controller 20. When a failure of the brake controller 20 is detected by the brake controller 20 itself, a failure detection signal Sabn is output from the brake controller 20 to the signal switching section 26.

[0025] The brake controller 20 generates a contactor command signal Sc2 for commanding the energization/de-energization of the brake coil contactor 23 based on the contactor command signal Sc1 to output the contactor command signal Sc2 to the signal switching section 26. The brake controller 20 also generates a brake control signal Sb2 for controlling the voltage to be applied to the brake coil 22 based on the brake command signal Sb1 to output the brake control signal Sb2 to the signal switching section 26.

[0026] The signal switching section 26 generates a contactor command signal Sc3 for commanding the energization/de-energization of the brake coil contactor 23 and a brake control signal Sb3 for controlling the voltage to be applied to the brake coil 22.

[0027] When the brake controller 20 is normal, specifically, the failure detection signal Sabn is not input, the contactor command signal Sc3 remains as the contactor command signal Sc2 and the brake control signal Sb3 remains as the brake control signal Sb2.

[0028]  On the other hand, when a failure of the brake controller 20 is detected, specifically, the failure detection signal Sabn is input, the signal switching section 26 invalidates the contactor command signal Sc2 and the brake control signal Sb2 from the brake controller 20 and controls the energization of the brake coil contactor 23 and the voltage of the brake coil 22 based on the contactor command signal Sc1 and the brake command signal Sb1 from the travel controller 21.

[0029] As described above, based on whether or not the failure has been detected in the brake controller 20, the signal switching section 26 performs switching between the validation and invalidation of the control performed by the brake controller 20. Then, when the failure of the brake controller 20 is detected, the signal switching section 26 invalidates the control performed by the brake controller 20 so as to directly operate the brake device 7 in response to the operation command signal generated by the travel controller 21.

[0030] Figure 3 is a flowchart illustrating a deceleration control operation of the brake controller 20 illustrated in Figure 1. The first computation section and the second computation section of the brake controller 20 simultaneously perform processing illustrated in Figure 3 in parallel. In Figure 3, the brake controller 20 first performs initial setting of a plurality of parameters required for the processing (Step S1). In this example, set as the parameters are a car speed (drive-sheave speed) V0 [m/s] used for the determination of car stop, a car speed V1 [m/s] at which the deceleration control is interrupted, a threshold value 10 [A] of the current value of the brake coil 22, and a first threshold value γ1 [m/s²] and a second threshold value γ2 [m/s²] of the car deceleration (γ1<γ2).

[0031] The processing after the initial setting is periodically repeated in a preset sampling cycle. Specifically, the brake controller 20 loads the signals from a sensor group including the hoisting-machine encoder 10 in a predetermined cycle (Step S2). Next, the car speed V [m/s] and the car deceleration γ [m/s²] are computed based on the signal from the hoisting-machine encoder 10 (Step S3).

[0032] Thereafter, it is determined whether or not the car 1 is currently performing an emergency stop operation (Step S4). More specifically, the brake controller 20 determines that the car 1 is performing the emergency stop operation when the car speed (motor rotation speed) is larger than the speed V0 for the determination of stop and the brake current value is smaller than the current value 10 for the determination of stop. When the emergency stop operation is not currently being performed, the deceleration control is not performed (Step S10).

[0033]  When the emergency stop operation is currently being per formed, it is then determined whether or not the car deceleration γ is larger than the first threshold value γ1 (Step S5). When a relation γ≤γ1 is established, the deceleration control is not performed (Step S10). On the other hand, when a relation γ>γ1 is established, the deceleration control is started (Step S6).

[0034] When the car 1 is brought to the emergency stop, the hoisting-machine motor 6 is de-energized. Therefore, from the generation of an emergency stop command to the actual exertion of the braking force, the car 1 is accelerated in some cases and decelerated in other cases depending on the imbalance between a load on the car 1 side and a load of the counterweight 2.

[0035] When the relation γ≤γ1 is established, the brake controller 20 determines that the car 1 is accelerated immediately after the generation of the emergency stop command and immediately applies a maximum braking force without performing the deceleration control so that the braking force is exerted as quickly as possible. On the other hand, when the relation γ>γ1 is established, the brake controller 20 determines that the car 1 is decelerated and performs the deceleration control so as to prevent the deceleration from being excessively large.

[0036] In the deceleration control, the brake controller 20 determines whether or not the car deceleration γ is larger than the second threshold value γ2 (Step S7). When the relation γ>γ2 is established, a deceleration control switch (not shown) is turned ON/OFF at a preset switching duty (for example, 50%) so as to keep the car deceleration γ down (Step S8). As a result, a predetermined voltage is applied to the brake coil 22 to control the braking force of the brake device 7.

[0037] When the relation γ≤γ2 is established, the deceleration control switch is left in the open state. Thereafter, the brake controller 20 determines whether or not to stop the control (Step S9). For the determination of whether or not to stop the control, whether or not the car speed V is less than the threshold value V1 is determined. When a relation V≥V1 is established, the processing directly returns to the input processing (Step S2). On the other hand, when a relation V<V1 is established, the deceleration control is terminated (Step S10). Then, the processing returns to the input processing (Step S2).

[0038] Next, Figure 4 is a flowchart illustrating an abnormality diagnosis operation of the brake controller 20 illustrated in Figure 1. The first computation section and the second computation section of the brake controller 20 invoke diagnosis processing illustrated in Figure 4 when each processing after the input processing (Step S2) illustrated in Figure 3 is completed.

[0039] In the abnormality diagnosis operation, the matching between the input values from the sensors or between the computation values obtained by the first computation section and the second computation section is determined (Step S11) More specifically, when a difference between the input values or between the computation values is within a predetermined range, it is determined that no abnormality occurs. Then, the processing returns to the subsequent processing illustrated in Figure 3. When the difference between the input values or between the computation values exceeds the predetermined range, it is determined that an abnormality occurs. Therefore, the failure detection signal Sabn is output to the signal switching section 26 (Step S12).

[0040] Figure 5 is a graph illustrating the relation between the first threshold value and the second threshold value of the car deceleration, which are set for the brake controller 20 illustrated in Figure 1, and the car position. The first threshold value γ1 and the second threshold value γ2 are set for each of the first computation section and the second computation section so as to change according to the car position, as illustrated in Figure 5. More specifically, each of the first threshold value γ1 and the second threshold value γ2 in the vicinity of the terminal landings is set so as to gradually increase toward the terminal landings.

[0041]  Figure 6 is a block diagram illustrating the signal switching section 26 illustrated in Figure 2. A change-over switch section 27 is switched according to the failure detection signal Sabn. The change-over switching section 27 illustrated in Figure 6 is in a state in which the failure of the brake controller 20 is not detected. Therefore, the brake control signal Sb2 from the brake controller 20 is directly output as the brake control signal Sb3.

[0042] When the failure of the brake controller 20 is detected, the change-over switch section 27 performs switching. As a result, a brake current command signal Sb4 generated in an output control logic circuit section 28 is output as the brake control signal Sb3. The output control logic circuit section 28 generates the brake current command signal Sb4 based on the brake command signal Sb1. from the travel controller 21, a brake switch signal from a brake switch (not shown) for detecting the position of the brake shoe 9, and a signal from a PWM generation circuit section 29.

[0043] Figure 7 is a graph showing an example of the brake current command signal Sb4 generated in the output control logic circuit section 28 illustrated in Figure 6. When receiving the brake command signal Sb1 for commanding the release of the braking force, the output control logic circuit section 28 outputs a predetermined current command value I1. Thereafter, when the separation of the brake shoe 9 from the brake drum 8 is detected at time t1, the output control logic circuit section 28 reduces the current command value to 12 (I1>I2). The current command value is reduced because a pull-in voltage, which is required to maintain the brake shoe 9 in a brake-release position, is smaller than a pull-in voltage, which is required to displace the brake shoe 9 from a braking position (release position) to the brake-release position (pull-in position).

[0044] The PWM generation circuit section 29 generates a signal for changing a duty ratio of PWM control. The duty radio of the PWM generation circuit section 29 can be changed by an operation of a rotary switch or the like. Specifically, a control voltage suitable for the brake device 7 corresponding to a target to be controlled is selected by operating the rotary switch or the like to preset the duty ratio. As a result, various types of the brake device 7 can be dealt with by using the common circuit configuration.

[0045] In the elevator apparatus described above, the operation command signal from the travel controller 21 is used to operate the brake device 7 when the failure of the brake controller 20 is detected. Therefore, the brake device 7 can perform the braking operation and the brake-release operation even in case of the failure of the brake controller 20. As a result, a passenger(s) can be prevented from getting stuck in the car 1.

[0046] In the case where the braking force of the brake device 7 is to be released when the failure of the brake controller 20 is detected, the preset pull-in voltage is applied to the brake coil 22 according to a state of the brake shoe 9 (by feeding back the state of the brake shoe 9). Thus, the voltage to be applied to the brake coil 22 can be minimized to prevent the burnout of the brake coil 22. In addition, power can be saved.

[0047] In the example described above, the deceleration control in case of the emergency stop is performed by the brake controller 20. However, the control on the brake device 7 by the brake controller 20 is not limited thereto. For example, control for reducing the operation noise of the brake device 7 may be performed.
Moreover, the failure of the brake controller 20 is detected by the brake controller 20 itself in the example described above. However, the failure of the brake controller 20 may be detected by the travel controller 21 or another monitoring device.
Further, the output control logic circuit section 28 is provided to the signal switching section 26 in the example described above. The position at which the output control logic circuit section 28 is provided is not limited thereto. The output control logic circuit section 28 can be provided, for example, in the travel controller 21.
Further, the destination of output of the signal may be changed over by the travel controller 21 without using the signal switching section 26 independent of the travel controller 21.

[0048] When the failure of the brake controller 20 is detected, the travel of the car 1 may be continued in a state in which the brake controller 20 is disconnected until a maintenance center is informed of the failure and a maintenance personnel performs inspection and repair. Alternatively, when the failure of the brake controller 20 is detected, the operation of the elevator apparatus may be stopped until the maintenance personnel performs inspection and repair after the car 1 is moved and stopped at a preset floor or the nearest floor in a state in which the brake controller 20 is disconnected.

[0049] Further, the number of the brake device 7 may be two or more.
Further, although the brake device 7 described in the above-mentioned example brakes the rotation of the drive sheave 5, the brake device may be a brake (rope brake or the like) which grips the suspension means to brake the car 1 or a brake (car brake) which is mounted to the car 1 to be engaged with a guide rail to brake the car 1.
Moreover, the suspension means may also be a belt.
Although the 1:1 roping system elevator apparatus is illustrated in Figure 1, the roping system is not limited thereto. For example, 2:1 roping may be used.
Further, although the car 1 is raised and lowered by the single hoisting machine 4 in the above-mentioned example, the elevator apparatus may use a plurality of hoisting machines.

Claims

1. An elevator apparatus, comprising:

a car;

a brake device for braking running of the car;

a travel controller for generating an operation command signal for operating the brake device to control a travel of the car; and

a brake controller for controlling a braking force of the brake device in response to the operation command signal,

wherein when a failure of the brake controller is detected, the control performed by the brake controller is invalidated so that the brake device is directly operated in response to the operation command signal.

2. An elevator apparatus according to claim 1, further comprising a signal switching section provided between the travel controller and the brake controller, and the brake device,
wherein the signal switching section performs switching between validation and invalidation of the control performed by the brake controller based on whether or not the failure of the brake controller has been detected.

3. An elevator apparatus according to claim 1, wherein the brake controller includes a duplexed computation section and is capable of detecting its own failure by comparing results of computations.

4. An elevator apparatus according to claim 1, wherein:

the brake device includes a brake shoe to be brought into contact with and separated away from a brake drum, a brake spring for pressing the brake shoe against the brake drum to apply a braking force thereto, and an electromagnetic magnet for separating the brake shoe away from the brake drum against the brake spring to release the braking force; and

a pull-in voltage preset according to a state of the brake shoe is applied to the electromagnetic magnet for releasing the braking force of the brake device when the failure of the brake controller is detected.

Drawing