Drum brake fault detection method

Abstract

The invention discloses a drum brake fault detection method, which comprises the following steps: acquiring winding coil voltage detected by a voltage sensor, winding coil current detected by a current sensor, displacement of a movable iron core detected by a displacement sensor, and on-off of a brake loop detected by a detection switch; according to the preset data, the winding coil voltage, the winding coil current and the displacement of the movable iron core, the relative displacement, the electromagnetic force and the compression spring force of a brake lining and a brake wheel of the drum brake, the current temperature of the winding coil and the band-type brake response time of the brake are determined; and according to the winding coil voltage, the winding coil current, the relative displacement of the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil and the band-type brake response time of the brake, whether the performance of the drum brake meets a preset standard or not is judged. According to the technical scheme, the performance of the brake can be detected more accurately and rapidly, and the professional requirement for workers is not high.

Description

Technical Field

[0001] The present invention relates to the technical field of elevator brake detection, and particularly relates to a method for detecting faults of a drum brake. Background Art

[0002] The elevator brake is one of the important working components to ensure the normal operation of the elevator. At the same time, the brake also serves as the braking component of the overspeed protection device for upward movement and the unexpected movement protection device, playing an important role in the safe operation of the elevator. In Shenzhen and across the country, faults such as car overshooting, bottom squatting, and opening and running caused by elevator brake failure are one of the main causes of elevator safety accidents that result in serious injuries or even deaths of passengers. Therefore, during the elevator maintenance process and for elevators in operation, monitoring the status of the brake to diagnose and warn of the fault status of the brake is crucial for ensuring the safe operation of the elevator.

[0003] Existing detection methods often only collect a lot of data through sensors. It is difficult for staff to obtain the key status parameters of the brake, so it is difficult to correctly determine the fault of the brake, and it has a relatively high requirement for the professional quality of personnel. Summary of the Invention

[0004] The main object of the present invention is to provide a method for detecting faults of a drum brake, aiming to provide a method for detecting faults of a drum brake that can obtain the key status parameters of the brake.

[0005] To achieve the above object, the present invention proposes a method for detecting faults of a drum brake. The detection method is applied to a drum brake fault detection device. The drum brake fault detection device includes a controller and a power supply module, a voltage sensor, a current sensor, a displacement sensor, and a detection switch that are electrically connected to the controller. The power supply module is used to supply power to the drum brake. The voltage sensor and the current sensor are respectively used to detect the winding coil voltage and the winding coil current of the drum brake. The displacement sensor is used to obtain the displacement of the moving iron core of the drum brake. The detection switch is used to detect the on / off of the braking circuit of the drum brake. The controller stores preset data;

[0006] The detection method includes:

[0007] Obtain the winding coil voltage detected by the voltage sensor, the winding coil current detected by the current sensor, the displacement of the moving iron core detected by the displacement sensor, and the on / off of the braking circuit detected by the detection switch;

[0008] Determine the relative displacement between the brake lining and the brake wheel of the drum brake, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake engagement response time of the brake according to the preset data, the winding coil voltage, the winding coil current, and the displacement of the moving iron core;

[0009] Judge whether the performance of the drum brake meets the preset standard according to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake engagement response time of the brake.

[0010] Optionally, the preset data includes the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm, and the vertical distance between the axis of the moving iron core and the hinge point of the brake arm;

[0011] The step of determining the relative displacement between the brake lining and the brake wheel specifically includes:

[0012] Determine the relative displacement between the brake lining and the brake wheel through a displacement calculation formula according to the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm, the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, and the displacement of the moving iron core;

[0013] The displacement calculation formula is:

[0014]

[0015] In the formula, δ is the relative displacement between the brake lining and the brake wheel, L is the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm, L1 is the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, and x is the displacement of the moving iron core.

[0016] Optionally, the displacement of the moving iron core includes the displacement of the moving iron core during the braking process;

[0017] The preset data includes the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, the vertical distance between the center line of the compression spring and the hinge point of the brake arm, and the moment of inertia of the brake arm;

[0018] The step of determining the compression spring force specifically includes:

[0019] Obtain the displacement of the moving iron core during the braking process detected by the displacement sensor and the braking action time;

[0020] Determine the compression spring force through a compression spring force calculation formula according to the displacement of the moving iron core during the braking process, the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, the vertical distance between the center line of the compression spring and the hinge point of the brake arm, the moment of inertia of the brake arm, the displacement of the moving iron core during the braking process, and the braking action time;

[0021] The calculation formula for the compression spring force is as follows:

[0022]

[0023] In the formula, F f is the compression spring force, J is the moment of inertia of the brake arm, L1 is the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, L2 is the vertical distance between the center line of the compression spring and the hinge point of the brake arm, x1 is the displacement of the moving iron core during the braking process, and t1 is the braking action time.

[0024] Optionally, the displacement of the moving iron core further includes the displacement of the moving iron core during the brake release process;

[0025] The steps for determining the electromagnetic force specifically include:

[0026] Obtain the displacement of the moving iron core during the brake release process detected by the displacement sensor and the brake release action time;

[0027] According to the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, the vertical distance between the center line of the compression spring and the hinge point of the brake arm, the moment of inertia of the brake arm, the compression spring force, the displacement of the moving iron core during the brake release process, and the brake release action time, determine the electromagnetic force through the electromagnetic force calculation formula;

[0028] The electromagnetic force calculation formula is as follows:

[0029]

[0030] In the formula, F e is the electromagnetic force, F f is the compression spring force, J is the moment of inertia of the brake arm, L1 is the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, L2 is the vertical distance between the center line of the compression spring and the hinge point of the brake arm, x2 is the displacement of the moving iron core during the brake release process, and t2 is the brake release action time.

[0031] Optionally, the winding coil voltage includes the holding voltage;

[0032] The winding coil current includes the holding current;

[0033] The preset data includes the reciprocal of the resistance temperature coefficient of the winding coil material, the test temperature, and the resistance value of the winding coil at the test temperature;

[0034] The steps for determining the current temperature of the winding coil specifically include:

[0035] Obtain the holding voltage detected by the voltage sensor and the holding current detected by the current sensor;

[0036] Determine the current temperature of the winding coil according to the holding voltage, the holding current, the reciprocal of the resistance temperature coefficient of the winding coil material, the test temperature, and the resistance value of the winding coil at the test temperature through the temperature calculation formula;

[0037] The temperature calculation formula is:

[0038]

[0039] In the formula, T x is the current temperature of the winding coil, K is the reciprocal of the resistance temperature coefficient of the winding coil material, T0 is the test temperature, R0 is the resistance value of the winding coil at the test temperature, u is the holding voltage, and i is the holding current.

[0040] Optionally, the drum brake fault detection device further includes a display module electrically connected to the controller;

[0041] After determining the relative displacement between the brake lining and the brake wheel of the drum brake, the electromagnetic force, the compression spring force, and the current temperature of the winding coil, the steps further include:

[0042] Determine the change curve with time according to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, and the current temperature of the winding coil;

[0043] Control the display module to display multiple said change curves.

[0044] Optionally, the steps of determining the brake response time specifically include:

[0045] Obtain the time when the power supply stops supplying power during the braking process and the time when the displacement sensor detects that the displacement of the moving iron core is zero;

[0046] Determine the brake response time according to the difference between the time when the power supply stops supplying power and the time when the displacement of the moving iron core is zero.

[0047] Optionally, the drum brake fault detection device further includes an alarm module electrically connected to the controller, and the alarm module is used to issue an alarm signal;

[0048] The preset data further includes the alarm ranges corresponding to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake response time of the brake;

[0049] The steps of judging whether the drum brake meets the preset standard specifically include:

[0050] Compare the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake response time of the brake with the corresponding alarm ranges.

[0051] If it is within the corresponding alarm range, the preset standard is met.

[0052] If at least one of them exceeds the corresponding alarm range, the preset standard is not met, and control the alarm module to send an alarm signal.

[0053] Optionally, the drum brake fault detection device further includes a warning module electrically connected to the controller, and the warning module is used to send a warning signal.

[0054] The preset data further includes the warning ranges corresponding to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake response time of the brake.

[0055] The steps before determining that the drum brake meets the preset standard further include:

[0056] When at least one of the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, and the current temperature of the winding coil exceeds the corresponding warning range, control the pre-tightening module to send a warning signal.

[0057] Optionally, the steps after the pre-tightening module sends a warning signal further include:

[0058] Control the display module to display the corresponding change curve.

[0059] In the technical solution of the present invention, the easily obtainable winding coil voltage, winding coil current, and the displacement of the moving iron core can be used to calculate the key state parameters of the brake through the preset data, namely the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake response time of the brake. When these key state parameters do not meet the preset standard, it is easy to determine the problem of the brake. In this way, the performance of the brake can be detected more accurately and quickly, and the professional requirements for the staff are not high. Description of the Drawings

[0060] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0061] Figure 1 It is a schematic structural diagram of a drum brake fault detection device for the hardware operating environment related to the solution of the embodiment of the present invention;

[0062] Figure 2 It is a schematic flowchart of the first embodiment of a method for detecting drum brake faults of the present invention;

[0063] Figure 3 It is a schematic flowchart of the second embodiment of a method for detecting drum brake faults of the present invention;

[0064] Figure 4 It is a schematic flowchart of the third embodiment of a method for detecting drum brake faults of the present invention;

[0065] Figure 5 It is a schematic flowchart of the fourth embodiment of a method for detecting drum brake faults of the present invention;

[0066] Figure 6 It is a schematic flowchart of the fifth embodiment of a method for detecting drum brake faults of the present invention;

[0067] Figure 7 It is a schematic flowchart of the sixth embodiment of a method for detecting drum brake faults of the present invention;

[0068] Figure 8 It is a schematic flowchart of the seventh embodiment of a method for detecting drum brake faults of the present invention;

[0069] Figure 9 It is a schematic flowchart of the eighth embodiment of a method for detecting drum brake faults of the present invention;

[0070] Figure 10 It is a schematic flowchart of the ninth embodiment of a method for detecting drum brake faults of the present invention;

[0071] Figure 11 It is a schematic flowchart of the tenth embodiment of a method for detecting drum brake faults of the present invention;

[0072] Figure 12 It is a general flowchart of the eleventh embodiment of a method for detecting drum brake faults of the present invention;

[0073] Figure 13 It is a structural schematic diagram of a drum brake.

[0074] The realization of the object of the present invention, its functional characteristics and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Specific embodiments

[0075] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0076] Refer to Figure 1 , Figure 1 It is a structural schematic diagram of a drum brake fault detection device for the hardware operating environment involved in the embodiment solution of the present invention.

[0077] As Figure 1 shown, the drum brake fault detection device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display) and an input unit such as a keyboard (Keyboard). Optionally, the user interface 1003 may further include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a wireless fidelity (WI-FI) interface). The memory 1005 may be a high-speed random access memory (Random Access Memory, RAM) or a stable non-volatile memory (Non-Volatile Memory, NVM), such as a disk memory. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0078] Those skilled in the art can understand that Figure 1 the structure shown in

[0079] As Figure 1 shown, in the memory 1005 as a storage medium, there may be included an operating system, a network communication module, a user interface module, and a detection program for drum brake faults.

[0080] In Figure 1In the drum brake fault detection device shown, the network interface 1004 is mainly used for data communication with a network server; the user interface 1003 is mainly used for data interaction with a user; the processor 1001 and the memory 1005 in the drum brake fault detection device of the present invention can be arranged in the drum brake fault detection device. The drum brake fault detection device calls the detection program for drum brake faults stored in the memory 1005 through the processor 1001 and executes the detection method for drum brake faults provided by the embodiments of the present invention.

[0081] Embodiments of the present invention provide a detection method for drum brake faults, and the detection method is applied to a drum brake fault detection device.

[0082] Refer to Figure 2 , Figure 2 which is a schematic flowchart of the first embodiment of a detection method for drum brake faults of the present invention.

[0083] The drum brake fault detection device includes a controller and a power supply module, a voltage sensor, a current sensor, a displacement sensor, and a detection switch electrically connected to the controller. The power supply module is used to supply power to the drum brake. The voltage sensor and the current sensor are respectively used to detect the winding coil voltage and the winding coil current of the drum brake. The displacement sensor is used to obtain the displacement of the moving iron core of the drum brake. The detection switch is used to detect the on / off of the braking circuit of the drum brake, and the controller stores preset data.

[0084] The detection method includes:

[0085] S10: Obtain the winding coil voltage detected by the voltage sensor, the winding coil current detected by the current sensor, the displacement of the moving iron core detected by the displacement sensor, and the on / off of the braking circuit detected by the detection switch;

[0086] Among them, according to the detection of the winding coil voltage by the voltage sensor and the detection of the braking circuit by the detection switch, it is possible to determine whether the start / stop of the elevator is synchronized with the on / off of the coil voltage. If not, it indicates that the elevator braking circuit is short-circuited. According to the detection of the winding coil voltage by the voltage sensor and the detection of the winding coil current by the current sensor, it is possible to detect whether the voltage and current of the coil are synchronized. If not, it indicates that the brake coil is damaged. According to the detection of the winding coil current by the current sensor and the detection of the displacement of the moving iron core by the displacement sensor, it is possible to detect whether the coil current and the displacement are synchronized. If not, it indicates that the ejector bolt of the brake is broken. Furthermore, through the detection of the voltage by the voltage sensor, it is possible to detect whether the effective value of the brake excitation voltage becomes smaller. If so, it indicates that the rectifier is damaged.

[0087] S20: Determine the relative displacement between the brake lining and the brake wheel of the drum brake, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake engagement response time of the brake according to the preset data, the winding coil voltage, the winding coil current, and the displacement of the moving iron core.

[0088] S30: Judge whether the performance of the drum brake meets the preset standard according to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake engagement response time of the brake.

[0089] Among them, the preset standard may be the braking capacity of a single set of brakes required by Article 12.4.2.1 of the national standard "Safety Code for the Manufacture and Installation of Lifts" (GB7588 - 2003) and Article 4.2.2.2 of the national standard "Lift Traction Machines" (GB / T24478 - 2009).

[0090] In the technical solution of this embodiment, the easily obtainable winding coil voltage, winding coil current, and the displacement of the moving iron core can be used to calculate the key state parameters of the brake through the preset data, that is, the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake engagement response time of the brake. When these key state parameters do not meet the preset standard, it is very easy to judge the problem of the brake. In this way, the performance of the brake can be detected more accurately and quickly, and the professional requirements for the staff are not high.

[0091] Refer to Figure 3 and Figure 13 , Figure 3 is a schematic flow chart of the second embodiment of a method for detecting faults of a drum brake according to the present invention, Figure 13 and

[0092] Based on the above first embodiment, in this embodiment, the preset data includes the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm, and the vertical distance between the axis of the moving iron core and the hinge point of the brake arm.

[0093] In the step of determining the relative displacement between the brake lining and the brake wheel in the method for detecting faults of the drum brake, it specifically includes:

[0094] S211: Determine the relative displacement between the brake lining and the brake wheel through a displacement calculation formula according to the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm, the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, and the displacement of the moving iron core.

[0095] The displacement calculation formula is as follows:

[0096]

[0097] In the formula, δ is the relative displacement between the brake lining and the brake wheel, L is the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm, L1 is the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, and x is the displacement of the moving iron core.

[0098] It should be understood that the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm and the vertical distance between the axis of the moving iron core and the hinge point of the brake arm can be known in advance according to the design parameters of the brake.

[0099] In the technical solution of this embodiment, since it is difficult to directly obtain the relative displacement between the brake lining and the brake wheel, it is changed to detect the displacement of the moving iron core through the displacement sensor, and then the relative displacement between the brake lining and the brake wheel can be calculated through the displacement calculation formula; when the relative displacement between the brake lining and the brake wheel is smaller than the preset standard, it indicates that the brake arm and / or the moving iron core of the brake are stuck, and when the relative displacement between the brake lining and the brake wheel is larger than the preset standard, it indicates that the brake lining of the brake is worn; in this way, it is possible to determine whether the brake is stuck or the brake lining is worn through the easily obtained displacement of the moving iron core.

[0100] It can be understood that the displacement sensor may drift, resulting in a larger or smaller detected displacement. However, during two detections within a short period of time, the deviations of the two values from the actual value are basically equal. Therefore, it is possible to detect the relative displacement between the brake lining and the brake wheel during the braking process and the relative displacement between the brake lining and the brake wheel during the brake release process, and then calculate the difference between the two relative displacements to determine whether the brake is stuck or the brake lining is worn.

[0101] Among them, the displacement of the moving iron core includes the displacement of the moving iron core during the braking process and the displacement of the moving iron core during the brake release process. Substituting the displacement of the moving iron core during the braking process and the displacement of the moving iron core during the brake release process into the above displacement calculation formula respectively, the relative displacement between the brake lining and the brake wheel during the braking process and the relative displacement between the brake lining and the brake wheel during the brake release process can be obtained, and then the difference between the two is calculated. If the difference is small, it indicates that the brake arm and / or the moving iron core of the brake are stuck, and if the difference is large, it indicates that the brake lining is worn.

[0102] Refer to Figure 4 and Figure 13 , Figure 4 is a schematic flow chart of the third embodiment of a method for detecting faults of a drum brake according to the present invention, Figure 13 is a schematic structural diagram of a drum brake.

[0103] Based on the first embodiment, in this embodiment, the displacement of the moving iron core includes the displacement of the moving iron core during the braking process; the preset data includes the perpendicular distance between the axis of the moving iron core and the hinge point of the brake arm, the perpendicular distance between the center line of the compression spring and the hinge point of the brake arm, and the moment of inertia of the brake arm.

[0104] In the step of determining the compression spring force in the method for detecting the failure of the drum brake, it specifically includes:

[0105] S221: Obtain the displacement of the moving iron core during the braking process detected by the displacement sensor and the braking action time;

[0106] S222: According to the displacement of the moving iron core during the braking process, the perpendicular distance between the axis of the moving iron core and the hinge point of the brake arm, the perpendicular distance between the center line of the compression spring and the hinge point of the brake arm, the moment of inertia of the brake arm, the displacement of the moving iron core during the braking process, and the braking action time, determine the compression spring force through the compression spring force calculation formula;

[0107] The compression spring force calculation formula is:

[0108]

[0109] In the formula, F f is the compression spring force, J is the moment of inertia of the brake arm, L1 is the perpendicular distance between the axis of the moving iron core and the hinge point of the brake arm, L2 is the perpendicular distance between the center line of the compression spring and the hinge point of the brake arm, x1 is the displacement of the moving iron core during the braking process, and t1 is the braking action time.

[0110] It can be understood that the perpendicular distance between the axis of the moving iron core and the hinge point of the brake arm, the perpendicular distance between the center line of the compression spring and the hinge point of the brake arm, and the moment of inertia of the brake arm can be known in advance according to the design parameters of the brake.

[0111] In the technical solution of this embodiment, since it is difficult to directly obtain the compression spring force of the brake, the displacement sensor can directly obtain the displacement of the moving iron core during the braking process and the braking action time, and then the compression spring force can be calculated through the preset data and the compression spring force calculation formula. When the compression spring force is less than the preset standard, it indicates that there is a fault in the compression spring of the brake; it can be analyzed from the working principle of the drum brake that when the brake brakes, the electromagnet winding coil is powered off, the compression spring pushes the brake arm to rotate, and the brake lining contacts the brake wheel, that is, the braking of the brake is driven by the compression spring force. When the compression spring force is too small, it may cause the braking process time to be too long.

[0112] Among them, It can be expressed as the acceleration of the moving iron core during the braking process. When the maximum acceleration during braking becomes smaller, it indicates that the compression spring force becomes smaller, that is, the compression spring force can be characterized by the maximum acceleration of the moving iron core during braking.

[0113] Referring to Figure 5 and Figure 13 , Figure 5 FIG. is a schematic flow chart of the fourth embodiment of a method for detecting faults in a drum brake according to the present invention. Figure 13 is a schematic structural diagram of a drum brake.

[0114] Based on the above third embodiment, in this embodiment, the displacement of the moving iron core further includes the displacement of the moving iron core during the brake release process.

[0115] The step of determining the electromagnetic force in the method for detecting faults in the drum brake specifically includes:

[0116] S231: Obtain the displacement of the moving iron core during the brake release process detected by the displacement sensor and the brake release action time;

[0117] S232: Determine the electromagnetic force through the electromagnetic force calculation formula according to the perpendicular distance between the axis of the moving iron core and the hinge point of the brake arm, the perpendicular distance between the center line of the compression spring and the hinge point of the brake arm, the moment of inertia of the brake arm, the compression spring force, the displacement of the moving iron core during the brake release process, and the brake release action time.

[0118] The electromagnetic force calculation formula is:

[0119]

[0120] In the formula, F e is the electromagnetic force, F f is the compression spring force, J is the moment of inertia of the brake arm, L1 is the perpendicular distance between the axis of the moving iron core and the hinge point of the brake arm, L2 is the perpendicular distance between the center line of the compression spring and the hinge point of the brake arm, x2 is the displacement of the moving iron core during the brake release process, and t2 is the brake release action time.

[0121] In the technical solution of this embodiment, it is known that when the brake is released, the electromagnetic coil of the electromagnet is energized, the electromagnet is attracted, and the brake arm is pushed by the ejector bolt to overcome the compression spring force to separate the brake lining from the brake wheel. When the electromagnetic force is difficult to directly obtain, it is easy to directly obtain the displacement of the moving iron core during the brake release process, the brake release action time, the relevant preset data, and the above-obtained compression spring force through the displacement sensor, and then the electromagnetic force can be determined through the electromagnetic force calculation formula. When the electromagnetic force is smaller than the preset standard, it indicates that there is a fault in the electromagnet.

[0122] Among them, It can be expressed as the acceleration of the moving iron core during the brake release process. When the maximum acceleration during brake release becomes smaller, it indicates that the electromagnetic force becomes smaller, that is, the electromagnetic force can be characterized by the maximum acceleration of the moving iron core during brake release.

[0123] Refer to Figure 6 , Figure 6 FIG. is a schematic flow chart of the fifth embodiment of a method for detecting faults of a drum brake according to the present invention.

[0124] Based on the above first embodiment, in this embodiment, the winding coil voltage includes a holding voltage; the winding coil current includes a holding current; the preset data includes the reciprocal of the resistance temperature coefficient of the winding coil material, the test temperature, and the resistance value of the winding coil at the test temperature.

[0125] In the step of determining the current temperature of the winding coil in the method for detecting faults of the drum brake, it specifically includes:

[0126] S241: Obtain the holding voltage detected by the voltage sensor and the holding current detected by the current sensor;

[0127] S242: Determine the current temperature of the winding coil through a temperature calculation formula according to the holding voltage, the holding current, the reciprocal of the resistance temperature coefficient of the winding coil material, the test temperature, and the resistance value of the winding coil at the test temperature;

[0128] The temperature calculation formula is:

[0129]

[0130] In the formula, T x is the current temperature of the winding coil, K is the reciprocal of the resistance temperature coefficient of the winding coil material, T0 is the test temperature, R0 is the resistance value of the winding coil at the test temperature, u is the holding voltage, and i is the holding current.

[0131] In the technical solution of this embodiment, it is known that the electromagnet coil has a certain internal resistance. After long-term operation, the inductance coil will heat up and affect the performance of the brake itself. If the temperature exceeds a certain range, the coil will burn out and cause the brake to malfunction. However, it is not easy to directly obtain the temperature of the coil inside the brake electromagnet. Therefore, this method determines the magnitude of the temperature by detecting the resistance value of the electromagnet winding coil (in the formula ), and the holding voltage and the holding current can be directly obtained through the voltage sensor and the current cut-off sensor, so that it is easy to determine whether the current temperature of the winding coil is normal.

[0132] Refer to Figure 7 , Figure 7Schematic diagram of the process of the sixth embodiment of a method for detecting faults in a drum brake according to the present invention.

[0133] Based on the above first embodiment, in this embodiment, the drum brake fault detection device further includes a display module electrically connected to the controller.

[0134] The steps after step S20 of the method for detecting faults in the drum brake further include:

[0135] S27: Determine the change curves with time according to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, and the current temperature of the winding coil;

[0136] S28: Control the display module to display a plurality of the change curves.

[0137] In the technical solution of this embodiment, the relationship between the state parameters of the brake and time is plotted into a plurality of the change curves, and the plurality of the change curves are displayed through the display module, which is more directly understandable for the staff to view.

[0138] Refer to Figure 8 , Figure 8 Schematic diagram of the process of the seventh embodiment of a method for detecting faults in a drum brake according to the present invention.

[0139] Based on the above first embodiment, in this embodiment, the steps of determining the brake response time in the method for detecting faults in the drum brake specifically include:

[0140] S251: Obtain the time when the power supply stops supplying power during the braking process and the time when the displacement sensor detects that the displacement of the moving iron core is zero;

[0141] Among them, the time when the power supply stops supplying power can be easily obtained according to the power supply parameters of the power supply to the brake.

[0142] S252: Determine the brake response time according to the difference between the time when the power supply stops supplying power and the time when the displacement of the moving iron core is zero.

[0143] It can be understood that when the elevator has a delayed brake, it is very easy to cause the car to overrun or bottom out, and it is easy to occur shearing and collision accidents, bringing danger to personnel. Therefore, it is very necessary to detect the brake response time of the brake.

[0144] In the technical solution of this embodiment, when the power supply stops supplying power, the brake starts to engage under the action of the compression spring. The time from when the power supply stops supplying power to when the brake is fully engaged (the displacement sensor detects that the displacement of the moving iron core is zero) is the brake response time. When the brake response time is longer than the preset standard, it means that the brake is engaged with a delay.

[0145] Reference Figure 9 , Figure 9 It is a flow chart of an eighth embodiment of a method for detecting drum brake failure according to the present invention.

[0146] Based on the above-mentioned sixth embodiment, in this embodiment, the drum brake fault detection equipment also includes an alarm module electrically connected to the controller, and the alarm module is used to issue an alarm signal; the preset data also includes the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the alarm range corresponding to the brake engagement response time.

[0147] Among them, the alarm range can be set according to the braking capacity of a single set of brakes required by Article 12.4.2.1 of the national standard "Safety Code for Elevator Manufacturing and Installation" (GB7588-2003) and Article 4.2.2.2 of the national standard "Elevator Traction Machine" (GB / T24478-2009).

[0148] Step S30 of the drum brake failure detection method specifically includes:

[0149] S31: comparing the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake holding response time with the corresponding alarm range;

[0150] S32: If it is within the corresponding alarm range, the preset standard is met;

[0151] S33: If at least one of them exceeds the corresponding alarm range, the preset standard is not met, and the alarm module is controlled to send an alarm signal.

[0152] In the technical solution of this embodiment, the alarm range set in advance is used to determine whether the corresponding value is within this range. As long as one of the values ​​is not within the corresponding alarm range, an alarm is issued to alert the staff and facilitate subsequent maintenance.

[0153] Further, while at least one of them exceeds the corresponding alarm range, control the display module to display the corresponding value so that the staff can directly obtain the parameter that does not meet the alarm range.

[0154] Refer to Figure 10 , Figure 10 which is a schematic flow chart of the ninth embodiment of a method for detecting faults of a drum brake according to the present invention.

[0155] Based on the above eighth embodiment, in this embodiment, the preset data further includes the warning ranges corresponding to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake response time of the brake.

[0156] The steps before determining that the drum brake meets the preset criteria further include:

[0157] S290: When at least one of the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, and the current temperature of the winding coil exceeds the corresponding warning range, control the pre-tightening module to send a warning signal.

[0158] In the technical solution of this embodiment, by setting the warning range, when the parameter value exceeds the warning range but has not exceeded the alarm range, the warning signal is sent through the warning module so that the staff can always pay attention to the corresponding parameter.

[0159] Refer to Figure 11 , Figure 11 which is a schematic flow chart of the tenth embodiment of a method for detecting faults of a drum brake according to the present invention.

[0160] Based on the above ninth embodiment, in this embodiment, the steps after step S290 of the method for detecting faults of the drum brake include:

[0161] S291: Control the display module to display the corresponding change curve.

[0162] In the technical solution of this embodiment, the change curve corresponding to the parameter that exceeds the warning range is displayed through the display module, which is convenient for the staff to observe.

[0163] In summary, refer to Figure 12 , Figure 12This is the overall flowchart of the eleventh embodiment of a detection method for drum brake faults in the present invention; based on the above embodiments, in this embodiment, through the voltage sensor, current sensor, the displacement sensor, and the detection switch, it is possible to detect whether the elevator start / stop is synchronized with the on / off of the coil voltage. If not synchronized, the detection is stopped, indicating an accidental short circuit in the elevator braking circuit; then, it is detected whether the coil voltage and current are synchronized. If not synchronized, the detection is stopped, indicating damage to the brake coil; then, it is detected whether the coil current and displacement are synchronized. If not synchronized, the detection is stopped, indicating a broken push rod bolt; then, it is detected whether the effective value of the excitation voltage becomes smaller. If it becomes smaller, the detection is stopped, indicating damage to the rectifier bridge; then, the brake release stroke is detected (the difference between the relative displacement of the brake lining and the brake wheel during the braking process and the relative displacement of the brake lining and the brake wheel during the release process calculated by the above displacement calculation formula). If the difference is small, it indicates jamming of the brake arm and / or the moving iron core of the brake. If the difference is large, it indicates wear of the brake lining, and the detection is stopped; then, the compression spring force calculated by the above compression spring force calculation formula and the maximum acceleration during braking are used. If the compression spring force becomes smaller and it also indicates that the maximum acceleration during braking becomes smaller, it indicates a fault in the compression spring, which may be aging or there is foreign matter; then, the electromagnetic force and the maximum acceleration during release are calculated by the above electromagnetic force calculation formula. If the electromagnetic force becomes smaller and it also indicates that the maximum acceleration during release becomes smaller, it indicates a fault in the electromagnet; then, the holding voltage and current are detected through the voltage sensor and the current sensor. If the ratio of the holding voltage to the current is too large, it indicates that the temperature of the coil is too high. Finally, the time required from power-off of the power supply to complete braking of the brake, that is, whether the braking response time is too large. If it is too large, it indicates delayed braking of the brake.

[0164] It should be noted that the above-described working process is only illustrative and does not limit the protection scope of the present invention. In actual applications, those skilled in the art can select some or all of them according to actual needs to achieve the purpose of the solution of this embodiment, and no limitation is imposed here.

[0165] In addition, for the technical details not described in detail in this embodiment, reference can be made to the detection method for drum brake faults provided in any embodiment of the present invention, and details will not be repeated here.

[0166] In addition, it should be noted that in this article, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. Without more limitations, the element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or system including the element.

[0167] The serial numbers of the embodiments of the present invention above are only for description and do not represent the superiority or inferiority of the embodiments.

[0168] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, in essence, or the part that makes a contribution to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as a read-only memory (ROM) / RAM, magnetic disk, optical disk), and includes several instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present invention.

[0169] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A detection method for drum brake faults, characterized in that The detection method is applied to a drum brake fault detection device, which includes a controller and a power supply module, a voltage sensor, a current sensor, a displacement sensor and a detection switch electrically connected to the controller. The power supply module is used to supply power to the drum brake. The voltage sensor and the current sensor are respectively used to detect the winding coil voltage and the winding coil current of the drum brake. The displacement sensor is used to obtain the displacement of the moving iron core of the drum brake. The detection switch is used to detect the on-off of the braking circuit of the drum brake. The controller stores preset data; The detection method includes: Obtaining the winding coil voltage detected by the voltage sensor, the winding coil current detected by the current sensor, the displacement of the moving iron core detected by the displacement sensor, and the on-off of the braking circuit detected by the detection switch; Determining the relative displacement between the brake lining and the brake wheel of the drum brake, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake engagement response time of the brake according to the preset data, the winding coil voltage, the winding coil current, and the displacement of the moving iron core; Judging whether the performance of the drum brake meets the preset standard according to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake engagement response time of the brake.

2. The detection method according to claim 1, characterized in that, The preset data includes the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm, and the vertical distance between the axis of the moving iron core and the hinge point of the brake arm; The step of determining the relative displacement between the brake lining and the brake wheel specifically includes: Determining the relative displacement between the brake lining and the brake wheel through a displacement calculation formula according to the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm, the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, and the displacement of the moving iron core; The displacement calculation formula is: In the formula, δ is the relative displacement between the brake lining and the brake wheel, L is the vertical distance between the midpoint of the brake lining and the hinge point of the brake arm, L1 is the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, and x is the displacement of the moving iron core.

3. The detection method according to claim 1, characterized in that, The displacement of the moving iron core includes the displacement of the moving iron core during the braking process; The preset data includes the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, the vertical distance between the center line of the compression spring and the hinge point of the brake arm, and the moment of inertia of the brake arm; The step of determining the compression spring force specifically includes: Obtaining the displacement of the moving iron core during the braking process detected by the displacement sensor and the braking action time; Determining the compression spring force through a compression spring force calculation formula according to the displacement of the moving iron core during the braking process, the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, the vertical distance between the center line of the compression spring and the hinge point of the brake arm, the moment of inertia of the brake arm, the displacement of the moving iron core during the braking process, and the braking action time; The compression spring force calculation formula is: Where, F f is the compression spring force, J is the moment of inertia of the brake arm, L1 is the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, L2 is the vertical distance between the center line of the compression spring and the hinge point of the brake arm, x1 is the displacement of the moving iron core during the braking process, and t1 is the braking action time.

4. The detection method according to claim 3, characterized in that, The displacement of the moving iron core also includes the displacement of the moving iron core during the brake release process; The step of determining the electromagnetic force specifically includes: Obtain the displacement of the moving iron core during the brake release process detected by the displacement sensor, and the brake release action time; According to the perpendicular distance between the axis of the moving iron core and the hinge point of the brake arm, the perpendicular distance between the center line of the compression spring and the hinge point of the brake arm, the moment of inertia of the brake arm, the compression spring force, the displacement of the moving iron core during the brake release process, and the brake release action time, determine the electromagnetic force through the electromagnetic force calculation formula; The electromagnetic force calculation formula is: Where F e is the electromagnetic force, F f is the compression spring force, J is the moment of inertia of the brake arm, L1 is the vertical distance between the axis of the moving iron core and the hinge point of the brake arm, L2 is the vertical distance between the center line of the compression spring and the hinge point of the brake arm, x2 is the displacement of the moving iron core during the opening process, and t2 is the opening action time.

5. The detection method according to claim 1, characterized in that, The winding coil voltage includes the holding voltage; The winding coil current includes the holding current; The preset data includes the reciprocal of the resistance temperature coefficient of the winding coil material, the test temperature, and the resistance value of the winding coil at the test temperature; The steps to determine the current temperature of the winding coil specifically include: Obtain the holding voltage detected by the voltage sensor and the holding current detected by the current sensor; According to the holding voltage, the holding current, the reciprocal of the resistance temperature coefficient of the winding coil material, the test temperature, and the resistance value of the winding coil at the test temperature, determine the current temperature of the winding coil through the temperature calculation formula; The temperature calculation formula is: Where, T x is the current temperature of the winding coil, K is the reciprocal of the resistance temperature coefficient of the winding coil material, T0 is the test temperature, R0 is the resistance value of the winding coil at the test temperature, u is the holding voltage, and i is the holding current.

6. The detection method according to claim 1, wherein The drum brake fault detection device further includes a display module electrically connected to the controller; After determining the relative displacement between the brake lining and the brake wheel of the drum brake, the electromagnetic force, the compression spring force, and the current temperature of the winding coil, the steps further include: Determine the change curve with time according to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, and the current temperature of the winding coil; Control the display module to display multiple said change curves.

7. The detection method according to claim 1, wherein The steps to determine the brake response time specifically include: Obtain the time when the power supply stops supplying power during the braking process and the time when the displacement sensor detects that the displacement of the moving iron core is zero; Determine the brake response time according to the difference between the time when the power supply stops supplying power and the time when the displacement of the moving iron core is zero.

8. The detection method according to claim 6, characterized in that, The drum brake fault detection device further includes an alarm module electrically connected to the controller, and the alarm module is used to emit an alarm signal; The preset data further includes the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the alarm range corresponding to the brake response time of the brake; The steps to determine whether the drum brake meets the preset standard specifically include: Compare the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake response time of the brake with the corresponding alarm range; If it is within the corresponding alarm range, it meets the preset standard; If at least one of them exceeds the corresponding alarm range, it does not meet the preset standard, and control the alarm module to emit an alarm signal.

9. The detection method according to claim 8, wherein, The drum brake fault detection device further includes a warning module electrically connected to the controller, and the warning module is used to issue a warning signal; The preset data further includes the warning ranges corresponding to the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, the current temperature of the winding coil, and the brake response time of the brake; The steps before determining that the drum brake meets the preset standard further include: When at least one of the winding coil voltage, the winding coil current, the relative displacement between the brake lining and the brake wheel, the electromagnetic force, the compression spring force, and the current temperature of the winding coil exceeds the corresponding warning range, control the pre-tightening module to issue a warning signal.

10. The detection method according to claim 9, wherein The steps after the pre-tightening module issues a warning signal further include: Control the display module to display the corresponding change curve.

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