JP7655652B2 - Dynamic torque diagnostic device and dynamic torque diagnostic method for hoist brake - Google Patents

Description

An embodiment of the present invention relates to a dynamic torque diagnostic device and a dynamic torque diagnostic method for a hoist brake.

If an elevator makes an emergency stop due to a power outage or the detection of an abnormality while it is running, 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 could cause a strong shock to the passengers inside the car, so by law, 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.

Conventionally, dynamic torque is often detected manually by an operator. There is also a method for determining 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. Furthermore, a method is also known in which, when the car is unoccupied, the car automatically operates at high speed and makes an emergency stop, and the brake braking force is calculated from the deceleration.

JP 2021-116148 A JP 2011-42480 A

However, the above-mentioned conventional example requires a new device to monitor the dynamic torque. Also, the conventional example of intentionally applying emergency braking when traveling at high speeds places a large load on elevator equipment such as ropes, and if this is done on a daily basis, it has the disadvantage of shortening the lifespan of various equipment.

In view of the above circumstances, the present invention aims to provide a dynamic torque diagnostic device and method for a hoist brake that can detect dynamic torque using software without adding new equipment for monitoring dynamic torque and can automatically measure it periodically without placing a load on the elevator equipment.

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 being equipped with a brake control unit, a motor control unit, and a brake dynamic torque determination unit.

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 hoist dynamic torque by adding the counterbalancing torque that compensates for the load imbalance 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.

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. 4 is a flowchart showing a processing procedure according to the embodiment of the present invention. 10 is a flowchart showing a processing procedure according to another embodiment of the present invention.

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

As shown in the figure, the car 1 is connected to a counterweight 3 by a main rope 2, and is raised (UP running) or lowered (DN running) by a hoist 4. The hoist 4 is equipped with two brakes (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 hoist 4 and a current detector 8 that detects the current flowing through the motor of the hoist 4 are provided, and the detected rotation speed and current detection value are output to an elevator control device 10.

The elevator control device 10 of this embodiment constitutes a dynamic torque diagnosis device for a hoisting 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.

The motor control unit 11 inputs the rotation speed from the rotation detector 7, which 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.

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

When a dynamic torque diagnosis command is input, the brake dynamic torque determination unit 13 outputs a determination command to the motor control unit 11 and the brake control unit 12 to perform the brake dynamic torque determination process.

The dynamic torque diagnostic command output unit 14 outputs a dynamic torque diagnostic command to the brake dynamic torque determination unit 13, taking into account passenger presence information and call registration information.

The judgment result output unit 15 outputs the judgment result for the calculated dynamic torque of the hoist 4 to a monitoring center, etc.

<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.

In the measurement process shown in FIG. 2, it is determined whether a certain amount of time has passed since the previous measurement. For example, if three days have passed since the previous measurement, it is determined that it is time to measure (step S1). The certain amount of time of "three days" is an example of a case in which 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 season, the measurement period may be changed depending on the ambient temperature and season.

Next, when the stopped state of the car 1 continues for a certain period of time, for example, "3 minutes" (step S2), it is confirmed that there is no user in the car by a load signal, a surveillance camera, etc. (step S3). Here, "3 minutes" as the certain period of time is only one 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 and image information from the surveillance camera, etc. It also confirms that there is no call registration information. When this 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 counterweight torque is calculated by measuring the torque of the counterweight when the car 1 is traveling at a constant speed each time it is measured.

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. For example, the brake control unit 12 releases the second brake 6 and holds the car 1 with only 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 brake static holding torque 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). Process (2) is executed to detect and record the hoist torque during this slow-speed running (step S8).

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 on the second brake 6, which is the other system.

<Determination process>
FIG. 3 illustrates the process of determining the measured dynamic torque.

If the measured dynamic torque is equal to or less than the 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 the value is within the reference value but the decrease from the previous measurement value exceeds a predetermined decrease.

When the dynamic torque measurement process is repeated a predetermined number of times, the brake, which has shifted from the sheave, will return to its original position by dragging the brake, resulting in a frictional state and the recovery of brake torque. When the dynamic torque returns to a reference value or higher (step S13 YES), the judgment process ends.

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

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

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

Conventionally, when regular inspections are performed manually on an annual basis, pass/fail judgments are based on a standard that estimates the amount of degradation after one year, but by increasing the frequency of inspections, it is possible to relax the standard value.

<Examples of changes>
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 in a state where 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.

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 embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

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 diagnostic command output unit, 15...judgment result output unit

Claims (4)

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 unbalance 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 . 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. 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 unbalance 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 . When the dynamic torque of the hoist brake is below a reference value, the dynamic torque determination process is repeated a plurality of 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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