阅读说明：本技术 用于诊断和/或维护制动器的方法、软件程序和制动设备 (Method, software program and brake system for diagnosing and/or maintaining a brake ) 是由 A.萨雷莱宁 J.拉帕莱宁 于 2019-06-28 设计创作，主要内容包括：本发明涉及用于诊断和/或维护制动器的方法,该制动器构造成将制动力施加到运输系统的曳引机。该方法包括：-控制制动器以开始制动控制动作,例如,制动器的打开和/或关闭动作；-监控制动器以检测制动器对制动控制动作的响应,其中,在响应的情况下,以预定方式检测响应；-测量从制动控制动作的开始的第一时间点直到监控制动器以检测响应的第二时间点的制动操作时间间隔；和,-如果直到制动操作时间间隔达到和/或超过预定阈值还未检测到响应,或,在制动操作时间间隔达到和/或超过预定阈值后检测到响应,则建立指示应该修改制动器操作的信息。本发明的另一方面是实现该方法的软件程序和配置为执行该方法的制动设备。(The present invention relates to a method for diagnosing and/or maintaining a brake configured to apply a braking force to a hoisting machine of a transport system. The method comprises the following steps: -controlling the brake to initiate a brake control action, e.g. an opening and/or closing action of the brake; -monitoring the brake to detect a response of the brake to a brake control action, wherein in case of a response the response is detected in a predetermined manner; -measuring a brake operation time interval from a first point in time of a start of a brake control action until a second point in time of monitoring the brake to detect a response; and-establishing information indicating that the brake operation should be modified if no response has been detected until or after the brake operation time interval reaches and/or exceeds the predetermined threshold. Another aspect of the invention is a software program implementing the method and a braking apparatus configured to perform the method.)

1. A method for diagnosing and/or maintaining a brake (B) configured to apply a braking force to a hoisting machine of a transport system, wherein the method comprises:

-controlling the brake (B) to start a brake control action, for example an opening and/or closing action of the brake (B);

-monitoring the brake (B) to detect a response of the brake (B) to a braking control action, wherein in case of a response, the response is detected in a predetermined manner;

-measuring a brake operation time interval (3,4) from a first point in time (5,7) of the start of a brake control action until a second point in time of monitoring the brake to detect a response; and the combination of (a) and (b),

-establishing information indicating that the brake operation should be modified if no response has been detected until or after the brake operation time interval (3,4) reaches and/or exceeds a predetermined threshold; and

characterized in that the information indicating that the operation of the brake (B) should be modified is established by a corrective action comprising one or more of the following:

-controlling the brake (B) to reduce the operating current of the electromagnets (51,53) of the brake (B) to reduce the brake operation time interval (3,4) for detecting a response, e.g. for resuming operation of the brake (B) within an allowed reaction time window;

-if the increase of the brake operation time interval (3,4) or the inverse of the increase of the brake operation time interval (3,4) for detecting a response reaches and/or exceeds a further threshold value, the transport system is taken out of service for safety reasons.

2. A method according to claim 1, wherein a brake control unit for controlling the brake (B), sensor means for monitoring the brake to detect the brake response, and timer means for measuring the brake operation time interval (3,4) are provided, wherein the timer means and/or the sensor means are provided as means separate from or integrated into the brake control unit.

3. A method according to claim 1 or 2, wherein the information is established to further indicate a specific type and/or severity of a fault or problem of the brake (B) or the transport system, such that a request to modify the operation of the brake (B) or the transport system is sent to the brake control unit, the transport system control unit or another unit outside the transport system, such as a maintenance unit.

4. Method according to any one of the preceding claims, wherein the information indicating that the operation of the brake (B) should be modified is established by comprising the following corrective actions:

-requesting maintenance brake (B) from a service center, e.g. from a remote server, as a cloud-based service over a telecommunication link.

5. A method according to any of the preceding claims, wherein the transport system is kept running continuously while the maintenance visit is being made by controlling the brake (B) to reduce the operating current of the electromagnets (51,53) of the brake (B) while requesting maintenance of the brake (B) from the service centre.

6. Method according to any of the preceding claims, wherein the operating current of the electromagnets (51,53) of the brake (B) is controlled such that the brake operating time interval (3,4) for detecting a response remains below or at a predetermined threshold value, and the controlled operating current of the electromagnets (51,53) of the brake (B) is monitored to determine wear of the friction linings of the ropes or belts of the transport system and/or misalignment of the friction linings.

7. The method according to claim 5 or 6, wherein the brake operation time interval (3,4) for detecting the response is measured by measuring a brake pick-up time (3) and/or a brake drop-out time (4), wherein the brake pick-up time (3) is for example less than 500 milliseconds and/or the brake drop-out time (4) is for example in the range of 50 to 100 milliseconds.

8. Method according to claim 7, wherein the brake magnet saturation and magnetic force are set to meet the locking and/or pick-up force requirements by measuring the brake pick-up time (3) and/or the brake drop-off time (4).

9. The method according to claim 7 or 8, wherein the brake pick-up time (3) is measured by one of:

-measuring from the point in time when the voltage is supplied to the electromagnets (51,53) of the brake (B) until the point in time when the proximity switch changes its state;

-starting from the point in time when the voltage is supplied to the electromagnets (51,53) of the brake (B) until the limit switch changes its state; and

-measuring from the point in time when voltage is supplied to the electromagnets (51,53) of the brake (B) until a peak value of the operating current of the electromagnets (51,53) of the brake (51) is detected.

10. The method according to claim 7 or 8, wherein the brake drop time (4) is measured by one of:

-starting from the point in time when the supply of voltage to the electromagnets (51,53) of the brake (B) is cut off, until the point in time when the proximity switch changes its state;

-starting from the point in time when the supply of voltage to the electromagnets (51,53) of the brake (B) is cut off, until the limit switch changes its state; and

-measuring from the point in time when the supply of voltage to the electromagnets (51,53) of the brake (B) is cut off until a peak value of the operating current or operating voltage of the electromagnets (51,53) of the brake (51) is detected.

11. A method according to claim 9 or 10, wherein the peaks of the operating current of the electromagnets (51,53) of the brake (B) are verified when the brake pads (52) of the brake (B) contact a surface to which a braking force is to be applied, such as a brake wheel, and the peaks verified at different points in time are used to determine wear and/or misalignment of the brake pads (52).

12. The method according to any of the preceding claims, wherein after the information is established, it is transmitted to or made accessible to a remote maintenance center or a mobile service unit or a local transport system control unit depending on the content of the information.

13. The method according to any of the preceding claims, wherein the transportation system is selected from one of an elevator, an escalator, a travelator, a cable car, a railway locomotive, a rail car, a roller coaster, a conveyor, a crane, a positioning unit, and a combination of several of the above individual units.

14. A software program which, when executed on a computer, implements the method of any preceding claim, wherein preferably the computer is a distributed computing system, part of which is located in a cloud computing system.

15. A braking apparatus for applying a braking force to a hoisting machine of a transport system, wherein the braking apparatus comprises a brake control unit for controlling the brakes (B), sensor means for monitoring the brakes to detect brake response, and timer means for measuring brake operation time intervals (3,4), wherein the timer means and/or the sensor means are provided as separate means from or integrated into the brake control unit and are configured to perform the method according to any one of claims 1 to 13.

Technical Field

The invention relates to a method for diagnosing and/or maintaining a brake configured to apply a braking force to a hoisting machine of a transport system, to a software program and to a braking apparatus.

Background

Transport systems such as elevators, escalators and the like usually have an electromechanical brake. For example, elevators have an electromechanical brake of the hoisting machine of the elevator as a safety device to apply a braking force onto the traction sheave or the rotating axis of the hoisting machine to brake the movement of the hoisting machine and thus brake the elevator car of the elevator. There are typically two independent brakes. During normal operation as well as during emergency operation, there are two similar brakes used in series. These two brakes must be able to stop the elevator car with a load of 125%. If one brake fails, the other brake must still hold the elevator car stationary at 115% load. The brake must therefore be dimensioned to be able to stop and hold an elevator car with a load of 125% (25% overload) in the elevator shaft. In addition, brakes are also used in rescue situations as well as emergency braking situations to stop the elevator car in the event of an operational failure, for example in the case of an overspeed of the elevator car. In addition, brakes are used to protect elevator passengers from accidental car movement in the event that a door is opened near a landing. The braking force may be generated by a suitable energy storage device, such as a compression spring, mounted on the brake. The brake is opened by supplying a sufficient amount of current to the electromagnet of the brake with the brake controller to oppose the thrust generated by the energy storage device (e.g., compression spring). The brake is closed when the current is reduced sufficiently that the thrust of the energy storage device dominates to cause movement of the brake armature toward the braking position. In EP 1701904B 1 it has been proposed to test the adequacy of the braking force. In the following, the opening and closing of the brake is defined by using the terms "pick-up" and "drop". Here, "pick-up" means the opening of the brake. The brake armature moves away from the braking position and the rotor (and traction sheave) can rotate freely. By "drop" is meant the closing of the brake. The brake armature moves to a braking position to brake movement of the rotor.

Traditionally, elevators are driven by a wire rope, which runs through a traction sheave of a traction machine. When the brake of the hoisting machine (also called hoisting machinery brake) is closed to stop the movement of the elevator car, the steel rope is slid over the traction sheave to prevent too high a deceleration of the elevator car, which may be uncomfortable or even dangerous for the elevator passengers. For example, in an emergency stop situation, the brake is controlled by the elevator safety chain to close. When the safety chain is opened, the current to the brake coil is interrupted and both brakes are applied simultaneously. While it is possible in the future to alleviate the problem of excessive deceleration by using more advanced safety circuits (e.g., electronic safety controllers) to allow the brakes to be closed at different times, coated ropes prevent avoiding excessive deceleration, which is not the case with conventional elevators having steel ropes and lower friction.

For this reason, a new type of coated hoisting ropes has now been introduced. These coated ropes may be conventional round ropes with a high friction coating or belts with a high friction coating, such as a polyurethane coating. In some elevators high friction ropes, such as belts, are used to reduce the traction sheave diameter, where such ropes without coating friction will not meet safety regulations. A smaller diameter means that the rotation frequency of the traction motor is higher, and therefore higher power can be obtained from a smaller motor.

On the other hand, the high friction coating is a feature of so-called KONE ultratapes (registered trademark), which are non-steel light ropes for high-rise elevators. The load bearing member is made of glass fibers, carbon fibers or other suitable synthetic fibers, rather than steel, secured within a (high friction) polymer jacket. Due to the light weight, these ropes can be used for longer hoisting distances than conventional ropes. With conventional steel ropes, the weight of the rope causes the rope to brake. With this new type of coated hoisting ropes, the friction between each rope and the corresponding traction sheave can be so high that the ropes do not slip sufficiently when the hoisting machinery brake has been closed to stop the movement of the elevator car. This may result in an increased deceleration of the elevator car.

In order to reduce the deceleration of the elevator car, the energy storage of the hoisting machinery brake can be readjusted to provide a lower braking force for the hoisting machine, thereby reducing the deceleration of the elevator car. However, readjustment tends to increase the operating time of the hoisting machinery brake, i.e. the time required to open and close the brake. On the other hand, the brake-off time should not exceed 350 ms, which can be defined as the reaction time in the case of an overspeed situation in which the elevator car approaches the shaft end, also referred to as ETSL time (ETSL: emergency terminal speed limit). In some cases the brake-off time should not even exceed 300ms, which may be defined as the reaction time in the case of an accidental car movement, also called UCMP time (UCMP: accidental cabin movement protection), in which the doors of the elevator car open near the landing. When a compression spring is used as an energy storage device of the traction machinery brake, the reaction time tends to increase with time due to the gradual decrease of the spring force. In the case of a lower braking torque, the reaction time of the brake limits the spring force adjustment to this braking torque, since a low spring force results in an excessive reaction time. In order to provide a sufficiently fast reaction time, the spring force adjustment window, i.e. the range of the spring force, is limited in accordance with the permissible size of the air gap between the electromagnet and the brake armature, so that without verification the reaction time can be reached in the conditions of the elevator site. The spring force adjustment window may be defined for a given spring disposed between the brake armature and the core as a range of heights of a spacer placed between the spring and the core to adjust a pretension of the spring. The height of the spacers is referred to as the LM dimension and the range of heights of the spacers is referred to as the LM dimension. At a given air gap between the electromagnet and the brake armature, the height of the spring, i.e. the dimension of the spring in the direction of the spring tension, reduces the height of the spacer. Thus, as the height of the spacer increases, the spring at a given air gap is pre-tensioned. At a given tension of the spring, the air gap increases as the height of the spacer increases.

Disclosure of Invention

It is therefore an object of the invention to adjust the deceleration time of a transport system.

This object is solved by the method of claim 1, the computer program product of claim 14 and the braking device of claim 15. Further developments and advantageous embodiments are defined in the dependent claims.

The method for diagnosing and/or maintaining a brake according to the present invention includes the steps of:

-controlling the brake to initiate a brake control action, e.g. an opening and/or closing action of the brake;

-monitoring the brake to detect a response of the brake to a brake control action, wherein in case of a response the response is detected in a predetermined manner;

-measuring a brake operation time interval from a first point in time of a start of a brake control action until a second point in time of monitoring the brake to detect a response; and the combination of (a) and (b),

-establishing information indicating that the brake operation should be modified if no response has been detected until or after the brake operation time interval reaches and/or exceeds the predetermined threshold.

The brake operation time interval lasts from the beginning of the first time point to the end of the second time point, i.e. includes the second time point. Thus, if measured from the first second to the third second, the duration of the brake operation time interval or the brake operation time interval itself is three seconds.

When no response to a brake control action (e.g. a decrease in the current and/or voltage of the electromagnet of the brake) has been detected (e.g. a change in the current and/or voltage of the electromagnet of the brake of a predetermined value is detected) within a predetermined threshold value, e.g. 500ms, a message is established indicating that the operation of the brake should be modified, e.g. an alarm. In one embodiment of the first alternative of the invention, the brake operation time interval (e.g. initiated by a timer means) runs from the brake control action and an alarm is generated when a certain value (e.g. 300ms or 500ms) is exceeded a predetermined threshold before a response of the brake control action has been detected or can be detected. By generating an alarm, which then indicates a brake failure, a message is established indicating that the brake operation should be modified. In this case, there is no need to monitor the brake before a response is detected. Monitoring is terminated once a predetermined threshold is reached or exceeded. In the case where there is no wait until the response is detected, there is no brake operation time interval from a first time point at which the brake control action is started to a second time point at which the response is detected. In contrast, in the case where no responsive information is detected or cannot be detected, the brake operation time interval ends at a predetermined threshold. In case no response is detected, i.e. a response time, but no response is detected during a predetermined threshold, a first alternative of the invention represents a fast way of establishing information indicating that the brake operation should be modified.

In a second alternative of the invention, information indicating that brake operation should be modified, such as an alarm, is established when a response to a brake control action (such as a decrease in current and/or voltage of the electromagnet of the brake) is detected (such as a detection of a change in current and/or voltage of the electromagnet of the brake of a predetermined value), but not within a predetermined threshold, such as 500 ms. A response is thus detected, but after the brake operation time interval reaches and/or exceeds a predetermined threshold, for example 500 milliseconds. In one embodiment of the second alternative of the invention, the brake operation time interval (e.g. initiated by a timer means) runs from the brake control action and an alarm is generated when a response is detected a certain value (e.g. 300ms or 500ms) later than a predetermined threshold for the brake operation time interval. In the case where the brake is monitored until the response is detected, there is a brake operation time interval from a first time point at which the brake control action is started to a second time point at which the brake is monitored to detect the response. By generating an alarm, which then indicates a brake failure, a message is established indicating that the brake operation should be modified. The alarm may contain information of the brake control action and the brake operation time interval for detecting the response, i.e. the response time. Thus, the second alternative of the invention allows not only to establish information indicating that the operation of the brake should be modified, but also to monitor information until a response is detected and to establish a brake operation time interval for detecting a response, i.e. a response time.

Thus, when using an elevator or escalator equipped with an electromechanical traction machinery brake and high friction ropes and/or belts, the method of the invention allows to meet the required reaction time of braking/deceleration, e.g. UCMP and ETSL braking. The method of the invention allows monitoring, regulating and controlling the brake so that the reaction time is within set limits even if the brake characteristics change during the service life of the brake.

The method according to the invention allows for a larger window/a larger range of values for setting the braking torque while ensuring the braking reaction time required by the elevator standards and codes. The method of the present invention can be used as a brake adjustment method that allows the manufacture of brakes that can be supplied to the front line at a full brake torque setting. The controlled braking torque ensures that the elevator is safe even when the counterweight and elevator car may not have final decoration and filler bits resulting in a balance of the elevator that is different from the calculated 50%.

The method is preferably performed by providing a brake control unit for controlling the brake, sensor means for monitoring the brake to detect the brake response, and timer means for measuring the brake operation time interval, wherein the timer means and/or the sensor means are provided as means separate from or integrated into the brake control unit. The internal clock of the computer may act as a timer device. Alternatively, the hardware added to a conventional transportation system may represent a timer device.

In another embodiment the transport system is provided with a transport system control unit which is operated separately from the brake control unit, wherein the timer means and/or the sensor means are provided separately from the transport system control unit or integrated into this unit.

The operating current of the electromagnet of the brake is preferably controlled such that the brake operating time interval for detecting a response remains below or at a predetermined threshold value, and the controlled operating current of the electromagnet of the brake is monitored to determine or at least evaluate wear and/or to determine misalignment of the friction lining of the rope or belt of the transport system. Preferably, the operating current of the electromagnet of the brake is automatically controlled, which enables an automated brake current setting, detection of the friction lining wear assessment and friction lining misalignment detection and thus pre-maintenance, while the transport system, e.g. an elevator, can still be used even if the performance is somewhat reduced (e.g. an increased delay in the start of a passenger pedal tray of a moving escalator or an elevator car of an elevator).

Preferably, the information indicates a particular type and/or severity of a fault or problem of the brake or transport system, such that a request to modify the operation of the brake or transport system is sent to the brake control unit, the transport system control unit or another unit outside the transport system, for example a maintenance unit. The brake operation time interval for detecting the response may be used to send a request to modify the operation of the brakes or the transport system, i.e. as content information of the request.

In an advantageous embodiment of the invention, the information indicating that the operation of the brake should be modified is established by a corrective action comprising one or more of the following:

-controlling the brake to reduce the operating current of the electromagnet of the brake to reduce the brake operation time interval for detecting a response, e.g. for resuming operation of the brake within an allowed reaction time window;

-requesting maintenance of the brakes as a cloud-based service from a service center, e.g. from a remote server, over a telecommunication link.

If the increase in the brake operating time interval or the inverse of the increase in the brake operating time interval for detecting a response reaches and/or exceeds a further threshold value, the transport system is taken out of service for safety reasons.

Preferably, the transport system is kept running continuously while the maintenance access is made by controlling the brake to reduce the operating current of the electromagnet of the brake while requesting maintenance of the brake from the service center. The operating current of the electromagnet of the brake is also referred to as the operating current of the brake, the brake operating current, the brake coil current or the brake coil current.

In other words: the timer device is introduced or integrated as a separate device into the elevator control unit or the brake control unit to measure the brake operation time interval or brake operation time gap, referred to as short brake operation time. When the brake operation time exceeds a given threshold, a need for corrective action is issued. The corrective action may be one or more of:

-reducing the operating current of the electromagnet of the brake by means of the brake controller to reduce the brake operation time, e.g. to resume the brake operation within an allowed reaction time window;

-requesting a maintenance brake as a cloud-based service from a service center over a telecommunication link, the service center being implementable as a remote server;

-if the increase in brake operation time is significant/evident/outside a predetermined range or value, the elevator is taken out of service for safety reasons;

-lowering the operating current of the brake while sending a maintenance request to the service centre, which means that the elevator can be kept running continuously while a maintenance access is in progress.

Preferably, the brake operation time interval for detecting the response is measured by measuring a brake pick-up time and/or a brake drop-off time, wherein the brake pick-up time is for example less than 500 milliseconds and/or the brake drop-off time is for example in the range of 50 to 100 milliseconds. The pick-up time is defined as the opening time, i.e. the time interval from the point of time when the (DC) voltage signal is applied to the coil of the brake electromagnet such that the coil current starts to increase gradually due to a given inductance of the coil, until the point of time when the brake is opened such that the brake armature has moved so much that opening can be detected (e.g. with an opening detection means). Accordingly, the drop time is defined as the off time, i.e. the time interval from the point in time at which the voltage signal of the brake coil is interrupted to the point in time at which the coil current gradually decreases so much that the brake armature has moved back into the closed position that this movement can be detected (e.g. with the closing detection means).

By measuring the brake pick-up time and/or the brake drop-off time, the brake magnet saturation and magnetic force can be set to meet the locking and/or pick-up force requirements. These requirements on the pick-up force are related to the opening means of the brake. The brake may have a compression spring which provides a pushing force (normal force) which pushes the brake pad against the surface of the object to be braked. The actual braking force is then calculated as the friction coefficient of the brake pads multiplied by the normal force. The pick-up force is the attractive force of the electromagnet which pulls the brake armature towards the electromagnet against the urging force of the compression spring. When a voltage is applied to brake the coil of the electromagnet, the current starts to rise, and therefore the attraction force of the electromagnet starts to rise. At some point, the current and therefore the attractive force exceed the thrust of the compression spring; this is the moment when the brake starts to open. This moment is not necessarily exactly the same as the moment when opening is detected with an opening detection means, such as a sensor device, but is directly related thereto, so that the deterioration of the brake can be monitored by an increase of the opening time.

It is particularly preferred that the brake pick-up time is measured by one of:

-measuring from the point in time when the voltage is supplied to the electromagnet of the brake until the point in time when the proximity switch changes its state;

-starting from the point in time when the voltage is supplied to the electromagnet of the brake, until the limit switch changes its state; and

-starting from the point in time when the voltage is supplied to the electromagnet of the brake, until a certain discontinuous peak pattern of the operating current of the electromagnet of the brake can be detected.

In another embodiment, the brake drop time is measured alternatively or in addition to the brake pick-up time by one of:

-measuring from the point in time when the voltage supply to the electromagnet of the brake is cut off, until the point in time when the proximity switch changes its state;

-starting the measurement from the point in time when the voltage supply to the electromagnet of the brake is cut off, until the limit switch changes its state; and

-starting from the point in time when the voltage supply to the electromagnet of the brake is cut off, until a certain discontinuous peak pattern of the operating current or operating voltage of the electromagnet of the brake can be detected.

The specific discontinuous peak pattern of the operating current of the electromagnet of the brake is advantageously verified when the brake pad of the brake contacts a surface to apply a braking force, such as a brake wheel, and the peaks verified at different points in time are used to determine and/or monitor wear and/or misalignment of the brake pad.

When the brake drop time is determined from the operating current of the brake, misalignment of the brake pads is preferably detected from two or more current peak patterns while the brake pads hit the respective surface or brake wheel. Misalignment of the brake pads can be advantageously evaluated from differences in the peak patterns of the operating current measured at different points in time (e.g., an hour, a day, a week, a month, etc., or in fractions of these intervals).

The brake magnetic force can be controlled by controlling the brake operating current. By measuring the brake pick-up time and the brake drop-off time, the brake magnet saturation and magnetic force can be set to meet the drop/pick-up force requirements. With too long a drop time, the brake operating current will be adjusted down until the required reaction time is met. If the pickup time is too long, the operating current will be adjusted to meet the required pickup time.

The operating current of the electromagnet of the brake can be selected/measured by using an existing brake control unit. The drop time may be measured by using an additional measuring device, such as a timer device. Alternatively, an internal clock of a server or local computer with which the method of the present invention is performed may be used.

After the information is established, it is preferably transmitted to or made accessible to the remote maintenance center or the mobile service unit or the local transport system control unit depending on the content of the information.

The setting of the operating current of the brake may be accomplished by setting a current command. A control module, separate from or integrated with the brake controller, will automatically pick up and drop the brake (single sided), measure the drop time and adjust the brake's operating current until the reaction time is within specification.

Such a method may comprise one, several or all of the following steps:

1) carrying out a single-side static braking test;

2) performing a rapid stop test and a deceleration measurement;

3) resetting the spring force;

4) verifying the braking torque by performing a one-sided braking test; and

5) setting the brake operating current to match the new spring force

The detection of friction lining wear can be performed because an increased air gap can be detected from an increased brake pick-up time. Preferably, the detection of friction lining wear occurs when the elevator performs a unilateral braking test.

The condition-based maintenance is preferably performed according to the invention by monitoring the brake lining wear by monitoring the pick-up time, wherein different pick-up times indicate a change in the air gap between the brake pad and the surface to which the braking force is to be applied, e.g. the brake wheel. In case the pick-up time exceeds a specified window/range of values, the elevator controller or brake controller may set an increased operating current of the brake or increase the elevator start-up delay or adjust the timing of the preliminary operation of the elevator. Changes in operating current outside of a predetermined range (also referred to as brake control current) required to ensure a specified reaction time result in a request to issue a preventative maintenance call to the service center. If the reaction time exceeds the allowed limit, the elevator will perform the last call and remain on the landing.

The transport system is advantageously selected from one of the group consisting of elevators, escalators, travelators, cable cars, rail cars, roller coasters, conveyors, cranes, positioning units, and combinations of the above individual units. It is particularly preferred that an elevator or escalator is used as the transport system. Most preferably, the transport system is an elevator.

Another aspect of the invention is a software program implementing the method according to the invention when executed on a computer. In the software program described above, the computer is preferably a distributed computing system, wherein a portion of the computing system is located/arranged/operated in a cloud computing system. The software program may be embodied as a computer program product or as a data carrier carrying data representing the software program.

The invention also relates to a brake apparatus for applying a braking force to a hoisting machine of a transport system, which brake apparatus is configured to perform the method according to the invention.

Drawings

Other aspects, features and advantages of the present invention will become apparent from the following description of exemplary embodiments, or from cooperation with the accompanying drawings.

Figure 1 is a diagram showing a family of magnet force curves of a brake and a corresponding family of positions of the brake as a function of time according to an exemplary embodiment of the invention,

fig. 2 is a graph showing the magnetic force of a brake according to an exemplary embodiment of the present invention, the magnetic force being a function of the air gap for different currents flowing in the coil of the electromagnet of the brake,

fig. 3 and 4 are schematic views showing magnetic flux densities of brakes having a current of 1A (fig. 3) and a current of 8A (fig. 4) flowing in coils of electromagnets of the brakes according to two other exemplary embodiments of the present invention, and

fig. 5 is a cross-sectional view of a brake and an air gap between an electromagnet and an armature of the brake, wherein a braking force is applied to the brake, according to another exemplary embodiment of the present invention.

Detailed Description

Now, exemplary embodiments of the present invention will be described in more detail.

Fig. 1 shows the results of a transient FEM analysis of brake operation according to the present invention. On a time scale of 4 seconds, a family of magnetomechanical curves for the brake from zero to 175kN and a corresponding family of curves at a position of zero to about 600 μm for the brake when ten voltages of 80 to 230 volts are applied are shown. The time scale is denoted by x, the position by y1 on the left side of the figure, and the magnetic force by y2 on the right side of the figure.

A family of ten curves 1 is shown, each curve 1 representing a magnetic force over time, with the upper curve having a peak of 175kN at 1.5 seconds being excited by applying an instantaneous voltage of 230V. The lower curve of the family of curve 1, which shows a peak at 2 seconds of 72.5kN, is excited by applying an instantaneous voltage of 80V. The 8 continuous curves between the lower and upper curves were excited by applying instantaneous voltages of 96.7V, 113.3V, 130V, 146.7V, 163.3V, 180V, 196.7V and 213.3V, respectively. Each voltage is applied as a DC voltage to the coil of the electromagnet of the brake according to the invention at zero seconds (see reference numeral 5) until 1.5 seconds, indicated by the dash-dot line 6. Instead of a DC voltage, an alternating voltage or a combination of DC and alternating voltages may be applied to increase the magnetic and magnetic energy of the braking system.

The compression spring is constituted by the brake such that when the magnetic force reaches a level of 40kN, the brake armature of the brake moves away from the surface of the brake to which the braking force is to be applied. Thus, a family of curves 2 is shown in fig. 1, each curve indicating that the brake is opened by moving the brake armature away from the surface of the brake to which braking force is to be applied within a fraction of a second by changing its position by about 600 microns. The opening of the brake occurs in response to the instantaneous voltage applied to the coil in time interval 3 of approximately 0.4 to 1.3 seconds. As the drive voltage decreases, the pickup time of the brake extends from about 0.4 seconds at 230V driving the coil of the brake electromagnet to about 1.3 seconds at 80V. Since the pickup time refers to the time from the application of the DC voltage signal to the coil of the brake electromagnet such that the coil current starts to gradually increase due to the high inductance of the coil until the brake opens such that the brake armature moves so much that opening can be detected with the opening detection means, the pickup time tends to become longer when the applied voltage is smaller, as shown in time interval 3 of fig. 1.

In the time interval of 1.5 to 2 seconds, the DC voltage of all curves of the family of curves 1 is set equal to 113.3V (see dash-dot lines 6 and 7), resulting in an increase in the magnetic force for the three lower curves and a decrease for the other curves.

At 2 seconds, indicated by the dotted line 7, a counter voltage is applied to the coil in the electromagnetic operation of the brake to reduce the magnetic force in the brake system as quickly as possible. The drop time is the time from the interruption of the voltage signal of the brake coil to the gradual reduction of the coil current due to the inductance of the coil to such an extent that the brake armature has moved back into the closed position that such a movement can be detected. The dropping of the brake, i.e. the closing of the brake, takes place according to the momentary voltage applied to the coil in a time interval 4 of about 2.2 to 3.3 seconds. As the drive voltage is reduced, the drop time of the brake is reduced from about 3.3 seconds at a voltage of 230V, which initially drives the coil of the brake electromagnet, to about 2.2 seconds at a voltage of 80V, in a time interval of 0 to 1.5 seconds. Thus, as the voltage is reduced, the resultant magnetic force and the resulting stored magnetic energy of the brake system is also reduced, allowing for a faster closing operation of the brake, since the back voltage of the electromagnetic operation is sufficient to reduce the magnetic energy of the brake system to a low enough voltage to cause the compression spring to release the brake to apply a braking force to the surface to which the braking force is to be applied.

By determining the pick-up time and/or the drop-off time, the drive voltage can be adjusted to meet the pick-up time and/or the drop-off time required in fig. 1 without requiring the transport system to be taken out of service for maintenance.

Fig. 2 is a graph showing the static magnetic force of a brake according to the invention as a function of the air gap for different currents flowing in the coil of the electromagnet of the brake. The air gap ranges from 0 to 1,21mm as indicated by the scale x. Depending on which of the ten curves monitored, the magnetic force ranged from 15 to 175 kN. The lower curve represents the brake comprising a coil through which the current of 1A flows. The upper curve represents the coil driven with a current of 8A. The curves between the lower and upper curves represent coils in which currents of 2A, 3,3A, 4A, 5,6A and 7A, respectively, are applied. These currents are DC currents. However, instead of a DC current, an alternating current or a combination of DC and alternating current may be applied to increase the magnetic and magnetic energy of the braking system. At a current of 8A, the increase in magnetic force is almost linear with decreasing air gap (left to right in x), and as the air gap decreases at a current of 1A, the force deviation (derivative) steadily increases.

The inductance is inversely proportional to the air gap or air gap length, such that as the air gap becomes longer, the inductance decreases. When the air gap increases, for example due to wear of the brake pads, the magnetic force decreases and the thrust of the compression spring tends to increase with respect to the magnetic force. When the air gap becomes wider, a higher braking current is required to open the brake. The drop time also includes the travel time of the brake armature from open to closed, which increases as the air gap widens. In addition, if the braking current is high, the braking iron of the core electromagnet is highly saturated. This also increases the drop time. It takes some time before the brake current decays to the point where the brake armature begins to move. The travel time is short, but the brake current is reduced and the hold time before the brake armature starts to move is the dominant time in the drop time. On the other hand, as the air gap between the brake armature and the magnetic core of the brake electromagnet increases, more brake current is required to pick up the brake.

Each of fig. 3 and 4 shows a schematic diagram of the magnetic flux density of the brake of the same brake B in cross-sectional views X and Y, in which currents of 1A and 8A (see reference numeral 30 in fig. 3 and 40 in fig. 4) flow in the coils of the electromagnet of the brake, respectively. Comparing the two figures, the distribution of the magnetic flux becomes more uneven as the current increases at the corners. There are three flux zones, for example, zone 31 and corresponding zone 41 in fig. 3, and four flux zones in fig. 4. In particular, the current of 8A results in a highly saturated material indicated by region 42 in fig. 4. Furthermore, the inductance is not linear, but the brake coil current is high, causing iron saturation around the brake coil. This saturation tends to slow the brake (see fig. 1, an increase in voltage at a given resistance results in an increase in current in the coil, an increase in pick-up time and drop time). This means that additional compression spring thrust is required to meet the pick and drop time requirements.

However, by controlling the operating current of the electromagnet of the brake, i.e. the drive current of the coil, such that the brake operating time interval is kept below or at a predetermined threshold value, the pick-up time and/or the drop-off time can be controlled with as little current as possible as shown in fig. 4, thereby avoiding saturation.

In fig. 5, a cross-sectional view of the brake B and the air gap 57 between the electromagnet of the brake B and the brake armature 52 of the brake B is shown. The electromagnet includes a magnetic core 51 and a coil 53. The cross-sectional view of brake B is shown in the X-Y plane. A spring 54 is arranged between the armature 52 and the core 51, the spring 54 being compressed as long as a current flows through the coil 53 to generate an attractive force between the electromagnet and the armature 52 that is greater than the spring thrust to keep the brake B open. Several springs may be used instead of the single spring 43. If the attractive force between the armature 52 and the electromagnet is reduced by reducing the current through the coil 53 and becomes smaller than the urging force of the spring 54, the brake B falls. Therefore, in the event of a power failure, the brake B automatically drops by the spring 54, separating the armature 52 and the magnetic core 51 from each other. A spacer 55, also called LM, is provided between the spring 54 and the core 51. The height 56 of the spacer 55 is selected to adjust the value of the air gap 57. Thus, the value of the air gap 57 is determined by the shape and size of the magnetic core 51, the height of the spring 54, and the height 56 of the spacer 55. The larger the size of the air gap 57, the smaller the thrust of the compression spring 54 and the magnetic force/braking torque of the electromagnet of the brake B should be.

The present invention provides a method that allows for a larger braking torque and spring force window or range than current brakes, yet ensures the braking reaction time required for UCMP and ETSL braking. Therefore, there is no need to: a given brake control module provides only one preset current value that must provide a sufficiently fast reaction time and full spring force. The method according to the invention allows to control and/or reduce and/or avoid excessive braking torque, which is not solved by conventional rope elevators with conventional single roping, which conventional rope slipping has a limited maximum deceleration. If an excessive current (force) results in an oversaturation of the magnet compared to the spring force that the magnetic force must overcome, the counter voltage spike may reduce the braking magnetic force to a state where the set spring force may create an initial air gap between the magnet and the armature. In this way, the initial air gap will be created by the counter voltage so that the applied spring force reaction time of the brake does not exceed the reaction time limit. The prior art friction lining wear and misalignment detection is based on preventive maintenance visits by service personnel.

By adjusting the brake according to the above-described method, it is possible to use friction linings having a greater fluctuation in the coefficient of friction than previously available.

With regard to the embodiment or embodiments discussed earlier herein, e.g. with regard to state-based maintenance of elevators, the technical feature or features already/already disclosed may also be present in another embodiment, e.g. with regard to escalators or cranes, unless it/they are/are specified to be absent or/they cannot be present for technical reasons.