Loosening and reversing protection device and method for steel wire rope of strong-drive elevator

Abstract

The invention provides a protection device and a protection method for loosening and reversing of a steel wire rope of a strong-drive elevator, which can effectively prevent the loosening and reversing of the steel wire rope, avoid sending of false alarms and improve user experience, an operation unit comprises a frequency converter and a driving motor, and the frequency converter is connected with the driving motor and supplies power to the driving motor; the driving motor drives an elevator car to operate, the current detection sensor comprises a current detection sensor and a control timing module, and the current detection sensor is used for detecting the current direction between the frequency converter and the driving motor; when the elevator descends, the current detection sensor detects the current direction between the frequency converter and the driving motor, when the current detection sensor detects the power generation current flowing from the driving motor to the frequency converter, the timing module is controlled to conduct timing, and when the duration time of the power generation current exceeds an alarm threshold value, the alarm module gives an alarm. And the control timing module sends an instruction to the running unit to control the elevator to stop running.

Description

Technical Field

[0001] The invention relates to the technical field of elevator control, and in particular to a wire rope loosening and reversal protection device and a protection method for a forced drive elevator. Background Art

[0002] Power-drive elevators usually use a permanent magnet synchronous motor (PMSM) to directly drive the elevator car. The motor is small and can be directly installed on the top or bottom of the elevator shaft. Other equipment such as the control cabinet can also be integrated in the shaft. Compared with traditional traction elevators, no independent machine room is required.

[0003] The strong drive elevator uses the inverter to drive the motor to rotate forward, wind up the wire rope and pull the elevator car upward, or rotate it in the reverse direction, release the wire rope and make the elevator car move downward. As the wire rope that pulls the elevator car, its loose rope reversal protection is extremely important. If the protection is not appropriate, it may cause the wire rope to break and the elevator car to run in the reverse direction, that is, the inverter drives the host to make the elevator go down, but the elevator car actually moves up because of the reverse rotation of the wire rope.

[0004] At present, the wire rope loosening and reversal protection is achieved by adding a wire rope touch switch. The wire rope will inevitably shake during the operation of the elevator. The shaking of the wire rope often easily causes the touch switch to malfunction, causing the elevator to produce an emergency stop protection, which brings a bad elevator riding experience to users. Summary of the invention

[0005] In view of the above problems, the present invention provides a wire rope loosening and reversal protection device and protection method for a forced-drive elevator, which can effectively prevent the wire rope from loosening and reversing, avoid sending false alarms, and improve user experience.

[0006] The technical solution is as follows: a wire rope loosening and reversing protection device for a strong drive elevator, comprising:

[0007] An operating unit, wherein the operating unit includes a frequency converter and a drive motor, wherein the frequency converter is connected to the drive motor and supplies power to the drive motor, and the drive motor drives the elevator car to operate.

[0008] It is characterized by further comprising:

[0009] A reversal detection unit, wherein the current detection sensor comprises a current detection sensor and a control timing module, and the current detection sensor is used to detect the current direction between the frequency converter and the drive motor;

[0010] When the elevator is descending, the current detection sensor detects the current direction between the inverter and the drive motor. When the current detection sensor detects the generated current flowing from the drive motor to the inverter, the control timing module starts timing. When the duration of the generated current exceeds the alarm threshold, the control timing module sends an instruction to the operating unit to control the elevator to stop running.

[0011] Furthermore, the current detection sensor and the control timing module are built into the frequency converter.

[0012] Furthermore, the drive motor is a permanent magnet synchronous motor.

[0013] A strong drive elevator, characterized by comprising the wire rope loosening and reversing protection device for the strong drive elevator according to claim 1.

[0014] A method for protecting a steel wire rope from loosening and reversing in a strong-drive elevator is implemented based on the steel wire rope from loosening and reversing in a strong-drive elevator according to claim 1, comprising the following steps:

[0015] When the elevator is descending, the current detection sensor continuously detects the current direction between the inverter and the drive motor;

[0016] When the current detection sensor detects the power generation current flowing from the drive motor to the inverter, the control timing module starts timing;

[0017] When the duration of the generated current exceeds the alarm threshold, the control timing module sends an instruction to the operating unit to stop the operation.

[0018] Furthermore, the alarm threshold range is 0.5S to 3S.

[0019] Furthermore, the method also includes the steps of: starting the emergency brake system to brake the elevator to prevent the car from continuing to move, and after the wire rope returns to normal state, the elevator is manually reset and the elevator resumes normal operation.

[0020] The wire rope loosening and reversal protection device of the strong drive elevator of the present invention can determine whether the wire rope is loose by detecting the change of the output current of the frequency converter, thereby avoiding the problem of malfunction of the traditional touch switch due to the shaking of the wire rope, improving the reliability and accuracy of the detection, avoiding the emergency stop of the elevator due to malfunction, and improving the user's elevator riding experience; the present invention also sets an alarm threshold for detecting the duration of the current of the present invention, effectively filtering out the interference of the current signal with too short a time, avoiding false alarms, further improving the reliability of the detection, and a reasonable alarm threshold setting can stop the elevator operation in time after the wire rope is loose, effectively preventing the reversal of the wire rope, and ensuring the safety of the elevator;

[0021] The wire rope loose rope reversal protection device of the strong drive elevator of the present invention can be integrated into the frequency converter control system, which simplifies the elevator system structure, improves the system integration and reliability, utilizes the existing elevator hardware for detection, does not need to add additional sensors or switches, and reduces the cost and installation difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a system block diagram of a wire rope loosening and reversing protection device for a forced drive elevator in Example 1;

[0023] Figure 2 It is a module block diagram of a wire rope loosening and reversing protection device for a strong drive elevator in an embodiment;

[0024] Figure 3 It is a module block diagram of another wire rope loosening and reversing protection device for a strong drive elevator in an embodiment;

[0025] Figure 4 It is a schematic diagram of the driving current and generating current of the strong drive elevator;

[0026] Figure 5 It is a schematic diagram of a method for protecting a wire rope from loose rope and reverse rotation in a forced drive elevator in an embodiment. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments, and people familiar with this technology can understand other advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0028] See Figure 1 , 2 A wire rope loosening and reversing protection device for a strong drive elevator of the present invention comprises:

[0029] The operation unit 100 includes a frequency converter 101 and a drive motor 102. The frequency converter 101 is connected to the drive motor 102 and supplies power to the drive motor 102. The drive motor 102 drives the elevator car to operate;

[0030] The driving motor 102 can usually adopt a permanent magnet synchronous motor. The permanent magnet synchronous host realizes power transmission and electric energy conversion through the interaction between the magnetic field generated by the stator and the magnetic field generated by the permanent magnet on the rotor. That is, when power transmission is required, the synchronous host consumes electric energy to generate transmission power; when the peripheral power is applied to the motor, it generates electric energy in turn. The frequency converter 101 can change the 380V, 50Hz industrial frequency power supply to the voltage and frequency required by the permanent magnet synchronous host through the rectifier and inverter, and generate power transmission for the permanent magnet synchronous host that can match the use needs;

[0031] The reverse detection unit 200 includes a current detection sensor 201 and a control timing module 202. The current detection sensor is used to detect the current direction between the inverter 101 and the drive motor 102. The current between the inverter 101 and the drive motor 102 includes a drive current and a generated current. Figure 4 As shown, the driving current is the current flowing from the inverter to the permanent magnet synchronous host, which converts electrical energy into kinetic energy, so that the permanent magnet synchronous host generates rotational power. When generating current, the current flowing from the permanent magnet synchronous host to the inverter converts kinetic energy into electrical energy. The external rotational force pulls the permanent magnet synchronous host to rotate, generating electrical energy.

[0032] In the embodiment of the present invention, the control timing module 202 mainly performs timing when the drive current of the inverter 101 flowing to the permanent magnet synchronous host is detected, specifically:

[0033] When the elevator is going down, the current detection sensor 200 detects the current direction between the frequency converter 101 and the drive motor 102. When the current detection sensor 201 detects the generated current from the drive motor 102 to the frequency converter 101, the control timing module 202 starts timing. When it is detected that the duration of the generated current exceeds the alarm threshold, the control timing module 202 sends an instruction to the operation unit 100 to control the elevator to stop running.

[0034] When the elevator goes up, it is the power of the main machine that winds up the wire rope and pulls the car upward. There is no loose wire rope and reverse movement.

[0035] The wire rope loosening and reversing protection device of the strong drive elevator of the embodiment determines whether the wire rope is loose by detecting whether the frequency converter outputs the driving current during the elevator descending process. Compared with the traditional wire rope touch switch, it avoids the false operation caused by the shaking of the wire rope and improves the accuracy of the loose rope reversing protection; by canceling the wire rope touch switch, the false alarm caused by shaking is reduced, the operation of the elevator is more stable, the unnecessary emergency stop protection is reduced, and the user's elevator riding experience is improved;

[0036] The touch switch can only be triggered when the wire rope loosens to a certain extent, and it is impossible to monitor the status of the wire rope in real time. In the embodiment, by continuously monitoring the current changes of the frequency converter, it is possible to promptly detect and take measures when the wire rope just begins to loosen, thereby improving safety and response speed. The wire rope loosening and reversal protection device of the strong drive elevator in the embodiment can realize more complex fault diagnosis and protection mechanisms by judging the current changes, thereby improving the intelligence level of the elevator system; in the embodiment, an alarm threshold for detecting the duration of the current of the invention is also set, which effectively filters out the interference of the current signal with too short a time, avoids false alarms, and further improves the reliability of detection. Reasonable alarm threshold setting can stop the elevator operation in time after the wire rope is loosened, effectively prevent the wire rope from reversing, and ensure the safety of the elevator.

[0037] See Figure 3 In one embodiment, a current detection sensor 201 and a control timing module 202 are provided and built into the frequency converter 101. In the prior art, a wire rope touch switch needs to be installed additionally, which increases the complexity and cost of the system. In the implementation, the existing frequency converter and permanent magnet synchronous host are used, and no additional hardware is needed, which reduces the cost and maintenance difficulty. Whether a loose rope reversal occurs is determined by its working characteristics. When the elevator goes down, the gravity of the car pulls the permanent magnet synchronous host to rotate, and the kinetic energy of the car is converted into electric energy and flows back to the frequency converter. If the wire rope connecting the host and the car is loose, the weight of the car cannot be transmitted to the host, and the kinetic energy cannot be converted into electric energy. The frequency converter needs to output a driving current to keep the host in a rotating state. If it is detected for 1 second, it can be determined that the wire rope of the host is loose, and the wire rope reversal is not avoided. A fault occurs and the operation stops immediately. It needs to be manually judged and reset before it can operate normally.

[0038] In an embodiment of the present invention, a forced drive elevator is further provided, comprising the wire rope loosening and reversal protection device of the forced drive elevator in the aforementioned embodiment.

[0039] See Figure 5 In an embodiment of the present invention, a method for protecting a steel wire rope from loosening and reversing in a forced-drive elevator is further provided, which is implemented based on the steel wire rope from loosening and reversing in a forced-drive elevator in the foregoing embodiment and includes the following steps:

[0040] Step S1: When the elevator is descending, the current detection sensor continuously detects the current direction between the inverter and the drive motor;

[0041] Step S2: When the current detection sensor detects the generated current flowing from the drive motor to the inverter, the timing module is controlled to start timing;

[0042] Step S3: When the duration of the generated current exceeds the alarm threshold, the control timing module sends an instruction to the operating unit to stop the operation.

[0043] In the embodiment of the present invention, the alarm threshold range is 0.5S to 3S, and 1S or 1.5S can be set during implementation. While effectively filtering out the current signal interference that is too short to avoid false alarms, it can also stop the elevator operation in time after the wire rope is loosened, effectively preventing the wire rope from reversing and ensuring the safety of the elevator. After many tests and verifications, it is determined that the driving current is generated and lasts for about 1 second when the elevator goes down, which will neither generate false alarms nor ensure the protection of wire rope loosening and reversal.

[0044] By adopting the method of the present invention, after detecting that the wire rope is loose, the emergency braking system can be immediately started to quickly brake the elevator to prevent the car from continuing to move and avoid further loosening or reversal of the wire rope. Specific fault information, such as loose wire rope, can also be displayed on the elevator control panel or display screen, so that maintenance personnel can quickly locate and solve the problem; the fault information and related operating data can also be recorded in the system log, which is convenient for subsequent analysis of the cause of the fault, maintenance and improvement; the fault information can also be transmitted to a remote monitoring center or a mobile device of the maintenance personnel through the network to realize remote alarm and monitoring. After confirming that the wire rope has returned to a normal state, it needs to be manually judged and reset before it can operate normally, thereby improving the safety of elevator operation.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0046] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A wire rope loosening and reversing protection device for a strong drive elevator, comprising: An operating unit, wherein the operating unit includes a frequency converter and a drive motor, wherein the frequency converter is connected to the drive motor and supplies power to the drive motor, and the drive motor drives the elevator car to operate. It is characterized in that Also includes: A reversal detection unit, wherein the current detection sensor comprises a current detection sensor and a control timing module, and the current detection sensor is used to detect the current direction between the frequency converter and the drive motor; When the elevator is descending, the current detection sensor detects the current direction between the inverter and the drive motor. When the current detection sensor detects the generated current flowing from the drive motor to the inverter, the control timing module starts timing. When the duration of the generated current exceeds the alarm threshold, the control timing module sends an instruction to the operating unit to control the elevator to stop running.

2. The wire rope loosening and reversing protection device of a strong drive elevator according to claim 1 is characterized in that: The current detection sensor and the control timing module are built in the frequency converter.

3. The wire rope loosening and reversing protection device of a strong drive elevator according to claim 1 is characterized in that: The driving motor is a permanent magnet synchronous motor.

4. A strong drive elevator, characterized in that: A wire rope loosening and reversal protection device for a strong drive elevator comprising the device described in any one of claims 1 to 3.

5. A method for protecting a steel wire rope from loosening and reversing in a strong-drive elevator, which is implemented based on the steel wire rope from loosening and reversing in a strong-drive elevator according to claim 1, characterized in that: The following steps are involved: When the elevator is descending, the current detection sensor continuously detects the current direction between the inverter and the drive motor; When the current detection sensor detects the power generation current flowing from the drive motor to the inverter, the control timing module starts timing; When the duration of the generated current exceeds the alarm threshold, the control timing module sends an instruction to the operating unit to stop the operation.

6. A method for protecting a steel wire rope from loosening and reversing in a strong drive elevator according to claim 5, characterized in that: The alarm threshold range is from 0.5S to 3S.

7. A method for protecting a steel wire rope from loosening and reversing in a strong drive elevator according to claim 5, characterized in that: The steps are also included: starting the emergency brake system to brake the elevator to prevent the car from continuing to move, and after the wire rope returns to a normal state, the elevator is manually reset and the elevator resumes normal operation.

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