Dynamic torque diagnostic device and dynamic torque diagnostic method for hoist brake

Abstract

To detect dynamic torque by means of software without adding new equipment for monitoring the dynamic torque and to enable periodic and automatic measurement of dynamic torque without applying a load to elevator equipment.SOLUTION: When there is no user in an elevator car, the car is held by a brake, and, in this state, hoisting machine torque is applied in a counterweight direction to perform slow-speed traveling control. The hoisting machine torque when a hoisting machine is rotated beyond static holding torque of the brake is detected. Dynamic torque of the hoisting machine is calculated by adding balance torque for compensating for load unbalance, to the detected hoisting machine torque. The braking force of the hoisting machine brake is diagnosed by whether the calculated dynamic torque exceeds a reference value or not.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention relates to a dynamic torque diagnosis device and a dynamic torque diagnosis method for a hoist brake. [Background technology]

[0002] When an elevator makes an emergency stop due to a power outage or the detection of an abnormality while it is running, the power to the hoist that drives the elevator is cut off and the brakes are closed to apply emergency braking. At this time, if the braking force is too strong, it will cause a strong shock to the passengers inside the car, so the law stipulates that the deceleration must be 1G (G: gravitational acceleration) or less. On the other hand, if the braking force is too weak, the car may not stop and may collide with the pit or the top of the elevator shaft, so an appropriate brake dynamic torque must be maintained.

[0003] Conventionally, dynamic torque detection is often done manually by workers. There is also a method to judge brake wear and sheave wear when emergency braking is applied by detecting sheave rotation with a magnetic detector and sheave vibration with an acceleration detector. In addition, there is also a method that automatically operates at high speed and makes an emergency stop when the car is unoccupied, and calculates the brake braking force from the deceleration. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-116148 [Patent Document 2] JP 2011-42480 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned conventional example requires a new device to monitor the dynamic torque. Also, the conventional example of intentionally applying emergency braking during high-speed UP travel places a large load on elevator equipment such as ropes, and if this is done on a daily basis, it shortens the lifespan of various equipment.

[0006] In view of the above circumstances, an object of the present invention is to provide a dynamic torque diagnosis device and a dynamic torque diagnosis method for a hoist machine brake that can detect dynamic torque using software without adding a new device for monitoring dynamic torque and that can automatically measure dynamic torque periodically without applying a load to the elevator equipment. [Means for solving the problem]

[0007] An embodiment for achieving the above object includes an elevator in which a car and a counterweight are suspended by a main rope and the car is moved by the rotational drive of a hoist, the elevator comprising a brake control unit, a motor control unit, and a brake dynamic torque determination unit.

[0008] The brake control unit holds the car with the hoist brake when there is no user in the car. The motor control unit applies hoist torque in the direction of the counterweight while the hoist brake holds the car, thereby performing slow-speed running control. The brake dynamic torque determination unit detects the hoist torque when the hoist rotates beyond the static holding torque of the brake, calculates the dynamic torque of the hoist by adding the counterbalancing torque that compensates for the load unbalance to the detected hoist torque, and diagnoses the braking force of the hoist brake based on whether the calculated dynamic torque exceeds a reference value. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. [Diagram 2] 4 is a flowchart showing a processing procedure according to the embodiment of the present invention. [Diagram 3] 10 is a flowchart showing a processing procedure according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Configuration of the embodiment> FIG. 1 is a block diagram showing a system configuration according to an embodiment of the present invention.

[0011] As shown in the figure, a car 1 is connected to a counterweight 3 by a main rope 2, and is raised (UP running) or lowered (DN running) by a hoisting machine 4. The hoisting machine 4 is equipped with two brake systems (double brakes): a first brake 5 and a second brake 6. In addition, a rotation detector 7 that detects the rotation speed of the motor that drives the hoisting machine 4, and a current detector 8 that detects the current flowing through the motor of the hoisting machine 4 are provided, and the detected rotation speed and current detection values ​​are output to an elevator control device 10.

[0012] The elevator control device 10 of the embodiment constitutes a dynamic torque diagnosis device for a hoist machine brake, and includes a motor control unit 11, a brake control unit 12, a brake dynamic torque determination unit 13, a dynamic torque diagnosis command output unit 14, and a determination result output unit 15.

[0013] The motor control unit 11 receives the rotation speed from the rotation detector 7 that detects the rotation speed of the hoisting machine 4, and controls the drive of the motor of the hoisting machine 4 based on the current detection value fed back from the hoisting machine 4.

[0014] The brake control unit 12 controls the application of the first brake 5 and the second brake 6 .

[0015] When the brake dynamic torque determination unit 13 receives a dynamic torque diagnosis command, it outputs a determination command to the motor control unit 11 and the brake control unit 12 to perform a brake dynamic torque determination process.

[0016] The dynamic torque diagnosis command output unit 14 outputs a dynamic torque diagnosis command to the brake dynamic torque determination unit 13, taking into account passenger presence / absence information and call registration information.

[0017] The determination result output unit 15 outputs the determination result for the calculated dynamic torque of the hoisting machine 4 to a monitoring center or the like.

[0018] <Processing procedure of the embodiment> Measurement processing FIG. 2 shows the procedure of the "measurement process" in the embodiment, and FIG. 3 shows the procedure of the "determination process" in the embodiment.

[0019] In the measurement process shown in Fig. 2, it is determined whether a certain amount of time has passed since the previous measurement, and if, for example, three days have passed since the previous measurement, it is determined that it is time to perform measurement (step S1). The certain amount of time "three days" is an example for when daily monitoring is desired, and can be set arbitrarily. In addition, since the braking force of the hoist brake changes depending on the ambient temperature and the season, the measurement cycle may be changed depending on the ambient temperature and the season.

[0020] Next, when the stopped state of the car 1 continues for a certain time, for example, "3 minutes" (step S2), it is confirmed that there is no user in the car by a load signal, a monitoring camera, or the like (step S3). Here, "3 minutes" as the certain time is only an example, and it may be, for example, a time period when there are no users, such as late at night or early in the morning. If it is assumed that there are no users, the elevator control device 10 confirms that there is no user in the car 1 based on the load signal or image information from the monitoring camera, etc. It also confirms that there is no call registration information. When it is confirmed, the dynamic torque diagnosis command output unit 14 outputs a dynamic torque diagnosis command to the brake dynamic torque determination unit 13. The brake dynamic torque determination unit 13 outputs a brake control command to the brake control unit 12. Then, a process (1) is executed to calculate the torque of the counterweight (counterweight torque) to compensate for the load imbalance (step S4). The counterbalancing torque is calculated by measuring the torque of the counterbalancing weight when the car 1 is traveling at a constant speed each time a measurement is made.

[0021] The brake control unit 12 can individually control the opening and closing of each of the brakes in one system, which is a double brake. The brake control unit 12, for example, releases the second brake 6 and holds the car 1 only with the first brake 5 of the other system (step S5). In this state, the hoist torque is applied in the direction of the counterweight (C / W) 3 (UP direction) to perform slow-speed running control (step S6). When the static holding torque of the brake is exceeded, the sheave of the hoist 4 rotates while dragging the brake, and it is determined whether a constant speed has been detected (step S7). A process (2) is executed to detect and record the hoist torque during this slow-speed running (step S8).

[0022] The brake dynamic torque is calculated by adding ((1)+(2)) the detected hoist torque and the balancing torque (torque that compensates for the load imbalance) (step S9). This is also performed for the second brake 6, which is another system.

[0023] <Determination process> FIG. 3 shows the process of determining the measured dynamic torque.

[0024] If the measured dynamic torque is equal to or less than a reference value (step S11), the dynamic torque measurement process shown in Fig. 2 is repeated a predetermined number of times, for example, three times (step S12). Here, the "reference value" refers to either a predetermined reference value or a value within the reference value but with a decrease from the previous measured value exceeding a predetermined decrease.

[0025] When the dynamic torque measurement process is repeated a predetermined number of times, the brake that has shifted from the sheave due to the drag of the brake will return to its original position, resulting in a frictional state, and the brake torque is expected to recover. When the dynamic torque returns to a reference value or higher (step S13 YES), the determination process ends.

[0026] If the dynamic torque falls below the reference value even after the dynamic torque measurement process has been repeated a predetermined number of times (NO in step S13), an alarm is output from the determination result output unit 15 to a monitoring center or the like (step S14).

[0027] In this way, according to the embodiment of the present invention, dynamic torque can be measured automatically and periodically without imposing a burden on the elevator equipment.

[0028] In addition, by regularly monitoring the torque of the hoist, it is possible to predict signs of torque decline and plan maintenance such as brake adjustment and replacement in advance.

[0029] Conventionally, when regular inspections are carried out manually on an annual basis, the pass / fail judgment is based on an estimated amount of degradation after one year, but by increasing the frequency of inspections, it is possible to relax the standard value.

[0030] <Example of change> In the above embodiment, when a decrease in dynamic torque is detected, stopping the elevator would result in a decrease in service quality, so the rated speed may be reduced to continue operation. This makes it possible to prevent the car 1 from reaching the end of the elevator due to the stop position being shifted due to a decrease in braking force even if sudden braking is applied when the dynamic torque is reduced. Also, instead of reducing the speed uniformly, it is possible to vary the speed reduction depending on the load and operating direction conditions, or to reduce the speed only near the end of the elevator. This makes it possible to maintain safe operation without compromising service quality for users.

[0031] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0032] REFERENCE SIGNS LIST 1...car, 2...main rope, 3...counterweight, 4...hoist, 5...first brake, 6...second brake, 7...rotation detector, 8...current detector, 10...elevator control device, 11...motor control unit, 12...brake control unit, 13...brake dynamic torque judgment unit, 14...dynamic torque diagnosis command output unit, 15...judgment result output unit

Claims

1. In an elevator in which a car and a counterweight are suspended by a main rope and the car is moved by the rotational drive of a hoist, a brake control unit that holds the car by a hoist brake when there is no user in the car; a motor control unit that applies a hoist torque in a counterweight direction while holding the car with a hoist brake, thereby performing slow-speed travel control; a brake dynamic torque determination unit that detects the hoist torque when the hoist rotates exceeding the static holding torque of the brake, calculates the dynamic torque of the hoist by adding a balancing torque that compensates for the load unbalance to the detected hoist torque, and diagnoses the braking force of the hoist brake based on whether the calculated dynamic torque exceeds a reference value or not, When the hoist brake has two systems, a first brake and a second brake, the brake control unit controls the brakes of the two systems to be opened and closed individually, The brake dynamic torque determination unit In detecting the dynamic torque of the first brake, the hoist torque when slow-speed travel control is performed in the counterweight direction with the second brake released is detected, and the detected hoist torque of the first brake is added to a counterweight torque that compensates for the load imbalance to calculate the dynamic torque of the first brake; In detecting the dynamic torque of the second brake, a hoist torque is detected when slow-speed travel control is performed in the counterweight direction with the first brake released, and the detected hoist torque of the second brake and the counterweight torque are added together to calculate the dynamic torque of the second brake; A dynamic torque diagnosis device for a hoist brake, which diagnoses the braking forces of the first brake and the second brake by comparing the calculated dynamic torques of the first brake and the second brake with a predetermined reference value.

2. When the dynamic torque of the hoist brake is below a reference value, the dynamic torque determination process is repeated a plurality of times; 2. The dynamic torque diagnosis device for a hoist brake according to claim 1, further comprising: a warning output to a monitoring center when the dynamic torque falls below the reference value even after a plurality of determination processes have been performed.

3. When there is no passenger in the car, the brakes hold the car in place, In this state, the hoist torque is applied in the direction of the counterweight to perform slow-speed running control. The torque of the hoist is detected when the hoist rotates beyond the static torque of the brake. A balancing torque that compensates for the load unbalance is added to the detected hoist torque to calculate the dynamic torque of the hoist. A method for diagnosing a dynamic torque of a hoist brake, comprising: diagnosing a braking force of the hoist brake based on whether or not a calculated dynamic torque exceeds a reference value, When the hoist brake has two systems, a first brake and a second brake, the brakes of the two systems are individually opened and closed, In detecting the dynamic torque of the first brake, the hoist torque when slow-speed travel control is performed in the counterweight direction with the second brake released is detected, and the detected hoist torque of the first brake is added to a counterweight torque that compensates for the load imbalance to calculate the dynamic torque of the first brake; In detecting the dynamic torque of the second brake, a hoist torque is detected when slow-speed travel control is performed in the counterweight direction with the first brake released, and the detected hoist torque of the second brake and the counterweight torque are added together to calculate the dynamic torque of the second brake; A method for diagnosing dynamic torque of a hoist brake, which diagnoses the braking forces of the first brake and the second brake by comparing the calculated dynamic torques of the first brake and the second brake with a predetermined reference value.

4. When the dynamic torque of the hoist brake is below a reference value, a process of determining the dynamic torque is repeatedly performed multiple times; 4. The method for diagnosing dynamic torque of a hoist brake according to claim 3, further comprising the step of outputting an alarm to a monitoring center when the dynamic torque falls below the reference value even after a plurality of determination processes have been performed.

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