Safety protection and control system of winch lifting motor and control method of safety protection and control system

Abstract

The invention discloses a safety protection and control system of a winch lifting motor and a control method of the safety protection and control system, and relates to the technical field of safety control of hoisting machinery. Comprising a lifting motor; the lifting winding drum is in transmission connection with the lifting motor; the motor control unit is electrically connected with the lifting motor and used for controlling starting, stopping and steering of the lifting motor; the limiting protection unit comprises a limiting switch arranged at the lifting winding drum and is used for triggering a limiting signal when the lifting winding drum rotates to the overwinding position; a temperature protection unit; and the safety control unit is in signal connection with the limiting protection unit, the temperature protection unit and the motor control unit and is used for receiving the limiting signal and the temperature protection signal and outputting a protection control instruction to the motor control unit according to the limiting signal and the temperature protection signal. According to the application, the safety control unit is in signal connection with key protection units such as limit protection and temperature protection, so that the reliability and consistency of system response are improved.

Description

Technical Field

[0001] This application relates to the field of safety control technology for lifting machinery, and in particular to a safety protection and control system for a winch hoisting motor and its control method. Background Technology

[0002] In industrial sectors such as mining, ports, and construction, winches are crucial lifting equipment, and their safety is paramount. Traditional winch control systems often employ single mechanical or electrical protection methods, such as overload protection and limit protection. However, under complex operating conditions such as explosion-proof environments, high temperatures, and frequent start-stop cycles, existing systems often suffer from the following problems:

[0003] Sensors used in explosion-proof areas are expensive and difficult to maintain;

[0004] The lack of multi-layered comprehensive protection makes it easy for accidents to occur due to the failure of a single protection system;

[0005] The inconvenience of resetting after overload protection affects the continuity of operation;

[0006] Insufficient protection against transient conditions such as motor startup and sudden current changes. Summary of the Invention

[0007] To address the aforementioned problems, this application provides a safety protection and control system for a winch hoisting motor, comprising:

[0008] Hoist motor;

[0009] The hoisting drum is connected to the hoisting motor via a drive.

[0010] The motor control unit is electrically connected to the hoisting motor and is used to control the start, stop and direction of the hoisting motor;

[0011] The limit protection unit includes a limit switch disposed at the hoisting drum, which is used to trigger a limit signal when the hoisting drum rotates to the overwind position;

[0012] The temperature protection unit includes a thermistor disposed inside the hoisting motor and a thermistor protection relay electrically connected to the thermistor, for sensing and responding to the internal temperature of the hoisting motor;

[0013] The safety control unit is connected to the limit protection unit, the temperature protection unit, and the motor control unit respectively, and is used to receive the limit signal and the temperature protection signal, and output protection control commands to the motor control unit accordingly.

[0014] In an optional embodiment, the system further includes an operation command unit and a power control and protection unit. The operation command unit is connected to the safety control unit and is used to receive and transmit lifting, lowering, fast, and slow operation commands. The power control and protection unit is connected to the main circuit of the hoisting motor and is used to limit the operating voltage and current, provide filtering, and monitor the real-time current.

[0015] In an optional embodiment, an overload limiting unit is further included. The overload limiting unit is signal-connected to the power control and protection unit and the safety control unit. It is used to determine the overload state based on the real-time current and, when an overload is determined, to cut off the lifting control circuit of the lifting motor through the safety control unit.

[0016] In an optional embodiment, an emergency stop circuit unit is further included, the emergency stop circuit unit including an emergency stop button, which, when triggered, causes the main power switch to trip to cut off the main power supply to the system, and the emergency stop button prevents the main power switch from being electrically reset before mechanical reset.

[0017] In an optional embodiment, a thermal overload relay and a time delay relay are also included. The thermal overload relay is connected in series in the main circuit and control circuit of the hoisting motor. The time delay relay is connected in the down-moving control circuit of the hoisting motor and is used to output a reset signal to the overload limiting unit after the hoisting motor reaches a preset delay during down-moving operation.

[0018] This application also provides a safety protection control method for a winch hoisting motor, applied to the aforementioned system, including:

[0019] Operation and control steps: Receive control commands and drive the hoisting motor and the hoisting drum to perform corresponding actions through the motor control unit;

[0020] Temperature monitoring and protection steps: The temperature protection unit continuously monitors the internal temperature of the hoisting motor, and when the internal temperature exceeds a first set threshold, the motor overheat protection is executed, cutting off the control circuit of the hoisting motor.

[0021] In an optional embodiment, an overwind limit protection step is further included: the limit protection unit monitors the rotational position of the hoisting drum, and when the hoisting drum is detected to have rotated to the overwind position, the limit switch is triggered to cut off the lifting control circuit of the hoisting motor.

[0022] In an optional embodiment, an emergency stop and reset step is also included: when the emergency stop button is triggered, the main power switch is controlled to trip to cut off the main power supply to the system; when the system restarts, the emergency stop button must be mechanically reset before the main power switch can be electrically reset.

[0023] In an optional embodiment, an overload protection and reset step is further included: the power control and protection unit monitors the real-time operating current of the hoisting motor; the overload limiting unit determines whether the load is overloaded; if overloaded, the hoisting control circuit of the hoisting motor is cut off and only descent operation is allowed; during the descent operation, the overload state is cleared by the time delay relay after a preset delay is reached.

[0024] In an optional embodiment, the system further includes an operation process and comprehensive monitoring steps: the power control and protection unit sets a start-up time parameter and performs protection based on the parameter during the start-up phase; during the operation phase, its filtering function is used to suppress current surges, and thermal overload protection is performed through the thermal overload relay; simultaneously, the power supply voltage and operating current are monitored in real time to comprehensively determine the operating status of the hoisting motor.

[0025] Due to the adoption of the above technical solution, this application has at least one of the following beneficial effects compared with the prior art:

[0026] 1. The safety control unit is connected to key protection units such as limit protection and temperature protection to receive various fault signals (such as limit, overheat, and overload) and output unified protection commands to the motor control unit accordingly, thereby improving the reliability and consistency of the system response.

[0027] 2. The power control and protection unit indirectly determines the load and motor status by monitoring electrical parameters such as voltage and current, replacing the expensive and fragile physical explosion-proof force sensor and reducing costs.

[0028] 3. The power control and protection unit has settable start-up time, filtering time, and current limiting functions. It can effectively suppress the inrush current during motor startup and the sudden current changes during operation, providing a smooth electrical environment for the motor. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] in:

[0031] Figure 1 A schematic diagram of the framework of a security protection and control system provided in an embodiment of this application;

[0032] Figure 2 This is a flowchart illustrating a security protection and control method provided in an embodiment of this application. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0034] The terms "first," "second," etc., used in this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0035] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] Existing winch hoisting systems commonly suffer from limited safety protection mechanisms and delayed response in high-risk operating environments such as explosion-proof environments. They typically rely solely on mechanical limit switches or thermal relays for overwind or overheat protection, failing to provide real-time and accurate identification of overload conditions. Using explosion-proof force sensors for load monitoring is costly, structurally complex, and difficult to maintain. Furthermore, in the event of overload or emergency stop, the system often experiences a complete power outage, failing to retain necessary descent functions to mitigate the danger and lacking a forced reset mechanism, thus increasing the risk of accidental restarts. These shortcomings make it difficult for existing technologies to simultaneously achieve safety, reliability, and operational continuity.

[0037] In view of this, the safety protection and control system of this application can be used in winch hoisting motors. By integrating a temperature protection unit (including a thermistor and a protective relay), a limit protection unit, and a safety control unit, and establishing a multi-signal linkage protection logic, it can achieve coordinated monitoring and rapid response of motor temperature, drum position, and operating status, effectively improving the intrinsic safety level of the system without relying on external force measuring devices. Figure 1 As shown, Figure 1A schematic diagram of the framework of a security protection and control system provided in an embodiment of this application includes:

[0038] The hoisting motor and hoisting drum are connected by a drive mechanism; as the actuator of the system, the hoisting motor is preferably a dual-speed three-phase asynchronous motor to meet the different needs of fast (efficient) and slow (precise) lifting operations. The motor and the hoisting drum are connected by a gear reducer or direct drive.

[0039] The motor control unit, electrically connected to the hoisting motor, is used to control the start, stop, and direction of the hoisting motor. The motor control unit is housed in a low-voltage electrical control cabinet, which mainly includes a main power switch, a contactor group (for controlling the motor's forward / reverse / high / low speed), and corresponding control circuits. Operating commands are input via a push-button box, which has clearly marked up and down buttons and selectable fast and slow speeds. After power is supplied, the operator can directly operate the push-button box to control the winch's movement.

[0040] The limit protection unit includes a limit switch located at the hoisting drum, used to trigger a limit signal when the hoisting drum rotates to the overwind position; the mechanical limit switch is precisely installed on the rotating shaft of the hoisting drum; when the hook is raised to the highest permissible position, the drum rotates to the corresponding number of revolutions, triggering the limit switch, and its normally closed contact opens; in this embodiment, a rotary cam limit switch is selected as the mechanical limit switch, while in other embodiments, the mechanical limit switch can be selected in other ways, and no limitation is made in this regard.

[0041] The temperature protection unit includes a thermistor installed inside the hoisting motor and a thermistor protection relay electrically connected to the thermistor. It senses and responds to the internal temperature of the hoisting motor. The thermistor, a positive temperature coefficient (PTC) type, is directly embedded within the hoisting electrode; its resistance increases significantly with increasing temperature. The thermistor protection relay monitors the thermistor, and its contacts are directly connected to the up / down control circuit of the winch motor. Once the internal temperature of the motor exceeds the set value of the thermistor, the thermistor resistance changes abruptly, driving the thermistor protection relay to activate. Its normally closed contact opens, thereby cutting off the motor's control circuit and providing immediate protection.

[0042] The safety control unit is connected to the limit protection unit, temperature protection unit, and motor control unit, respectively. It receives limit signals and temperature protection signals and outputs protection control commands to the motor control unit accordingly. The safety control unit is implemented using a programmable logic controller (PLC) or a combination of dedicated safety relays. It receives overwind signals from limit switches, overheat signals from thermal relays, and operating commands (ascending, descending, etc.). Its internal logic processes data according to preset priorities and outputs the final control command to the contactor coils of the motor control unit.

[0043] In this embodiment, the control priority is emergency stop, followed by overwind, overheat, and overload; for example, even if the operator presses the up button, if the safety control unit receives an overwind signal at the same time, the command it outputs to the up contactor will be prohibited.

[0044] In summary, the safety protection and control system of this embodiment includes: a hoisting motor; a hoisting drum, drivenly connected to the hoisting motor; a motor control unit, electrically connected to the hoisting motor, used to control the start, stop, and direction of the hoisting motor; a limit protection unit, including a limit switch disposed at the hoisting drum, used to trigger a limit signal when the hoisting drum rotates to the overwind position; a temperature protection unit; and a safety control unit, signal-connected to the limit protection unit, the temperature protection unit, and the motor control unit respectively, used to receive the limit signal and the temperature protection signal, and output protection control commands to the motor control unit accordingly. This application improves the reliability and consistency of the system response by signal-connecting the safety control unit with key protection units such as limit protection and temperature protection.

[0045] The safety protection and control system also includes an operation command unit and a power control and protection unit. The operation command unit is connected to the safety control unit and is used to receive and transmit lifting, lowering, fast and slow operation commands. The power control and protection unit is connected to the main circuit of the hoisting motor and is used to limit the operating voltage and current, provide filtering, and monitor the real-time current.

[0046] The power control and protection unit includes:

[0047] Voltage and current limiting: The maximum operating voltage and output current of the motor are limited by an internal algorithm, thereby indirectly limiting the maximum output torque.

[0048] Filtering function: Built-in adjustable filter circuit can smooth out current surges caused by load fluctuations and power grid fluctuations, preventing malfunctions.

[0049] Real-time current monitoring: The motor operating current is sampled in real time through the built-in current transformer, providing a data basis for subsequent overload judgment.

[0050] It should be clarified that different currents can be limited for different operations; for example, the current limit for fast operation is greater than the current limit for slow operation.

[0051] The specific process is described in detail below:

[0052] The operator selects rapid ascent via the button box. The signal is transmitted to the safety control unit. After the unit checks that the limit switches and overheating are normal, it sends a rapid ascent command to the motor control unit. At the same time, the safety control unit switches the power control and protection unit to the rapid current limit mode. The motor starts, and the power controller begins to work. During the start-up period, the starting current is allowed, and after entering operation, the current is continuously monitored and filtered.

[0053] The safety protection and control system also includes an overload limiting unit, which is connected to the power control and protection unit and the safety control unit. It is used to determine the overload status based on the real-time current and, when an overload is determined, to cut off the lifting control circuit of the lifting motor through the safety control unit.

[0054] The parameter setting method of the overload limiting unit is described below with reference to an embodiment:

[0055] Lift the rated working load and, under stable operating conditions, read the measured current parameter value from the power controller.

[0056] Set the protection current parameter starting from the measured current parameter value at this time minus 3A.

[0057] Each parameter is set, and the effect is tested to verify that the rated working load can be lifted normally.

[0058] Then test with 1.1 times the rated working load. The target result is that it cannot be lifted.

[0059] If it does not meet the requirements, fine-tune the current setting value and test repeatedly until the ideal state of being able to lift at the rated current and not being able to lift at 1.1 times the rated current is reached. Then it meets the overload limit requirements.

[0060] The safety protection and control system also includes an emergency stop circuit unit, which includes an emergency stop button. When the emergency stop button is triggered, it can trip the main power switch to cut off the main power supply to the system. The emergency stop button also prevents the main power switch from being electrically reset before it is mechanically reset.

[0061] In one embodiment, the emergency stop button is a mechanically self-locking button, connected in series in the control circuit and linked to the trip coil of the main power circuit breaker via auxiliary contacts. When the operator presses the emergency stop button, its normally closed contact immediately opens, causing the main power circuit breaker to trip and disconnect the 380V main power and 24V control power of the entire system. Simultaneously, the emergency stop button enters a mechanically locked state. Even if an external party attempts to remotely or automatically close the main power circuit breaker, because the emergency stop button has not been manually rotated to reset, its auxiliary contacts remain open, preventing the main power circuit breaker from completing an electrical reset. This ensures that the system cannot be restarted until the fault is identified and resolved.

[0062] The safety protection and control system also includes thermal overload relays and time delay relays. The thermal overload relays are connected in series in the main circuit and control circuit of the hoisting motor; the time delay relays are connected in the downward control circuit of the hoisting motor and are used to output a reset signal to the overload limiting unit after the hoisting motor reaches the preset delay during downward operation.

[0063] In one embodiment, a thermal overload relay is connected in series in the main circuit of the hoisting motor. Its normally closed auxiliary contact is connected to the control circuit. When the motor runs for a long time, causing the current to remain high (although it does not reach the overload threshold, it causes the temperature to accumulate), the thermal relay will activate and disconnect the control circuit to achieve redundant thermal protection.

[0064] Simultaneously, a time-delay relay is installed in the descent control circuit. When the operator executes the descent command, the coil of the time-delay relay is energized and begins timing (e.g., set to 2 seconds). During the delay, the overload limit state remains locked; after the delay ends, the normally open contact of the time-delay relay closes, sending a pulse reset signal to the power controller to release the descent prohibition state previously triggered by overload.

[0065] This application also provides a safety protection and control method for a winch hoisting motor, applicable to the system described in the above embodiments, such as... Figure 2 As shown, Figure 2 A flowchart illustrating a security protection control method provided in an embodiment of this application includes:

[0066] Operation and control steps: Receive control commands and drive the hoisting motor and hoisting drum to perform corresponding actions through the motor control unit;

[0067] Temperature monitoring and protection steps: The internal temperature of the hoisting motor is continuously monitored by the temperature protection unit, and when the internal temperature exceeds the first set threshold, the motor overheat protection is executed to cut off the control circuit of the hoisting motor.

[0068] It also includes an overwind limit protection step: the limit protection unit monitors the rotation position of the hoisting drum, and when the hoisting drum is detected to have rotated to the overwind position, the limit switch is triggered to cut off the hoisting motor's lifting control circuit.

[0069] The safety protection control method also includes emergency stop and reset steps: when the emergency stop button is triggered, the main power switch is tripped to cut off the main power supply to the system; when the system restarts, the emergency stop button must be mechanically reset before the main power switch can be electrically reset.

[0070] The safety protection and control method also includes overload protection and reset steps: the real-time operating current of the hoisting motor is monitored by the power control and protection unit; the overload limiting unit determines whether the load is overloaded; if overloaded, the hoisting control circuit of the hoisting motor is cut off and only the descent operation is allowed; during the descent operation, the overload state is cleared by the time delay relay after the preset delay is reached.

[0071] The safety protection and control method also includes operation process and comprehensive monitoring steps: the start-up time parameter is set through the power control and protection unit, and protection is carried out according to the parameter during the start-up phase; during the operation phase, its filtering function is used to suppress current surges, and thermal overload protection is carried out through the thermal overload relay; at the same time, the power supply voltage and operating current are monitored in real time to comprehensively determine the working status of the hoisting motor.

[0072] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0073] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0074] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0075] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A safety protection and control system for a winch hoisting motor, characterized in that, include: Hoist motor; The hoisting drum is connected to the hoisting motor via a drive. The motor control unit is electrically connected to the hoisting motor and is used to control the start, stop and direction of the hoisting motor; The limit protection unit includes a limit switch disposed at the hoisting drum, which is used to trigger a limit signal when the hoisting drum rotates to the overwind position; The temperature protection unit includes a thermistor disposed inside the hoisting motor and a thermistor protection relay electrically connected to the thermistor, for sensing and responding to the internal temperature of the hoisting motor; The safety control unit is connected to the limit protection unit, the temperature protection unit, and the motor control unit respectively, and is used to receive the limit signal and the temperature protection signal, and output protection control commands to the motor control unit accordingly.

2. The system according to claim 1, characterized in that, It also includes an operation command unit and a power control and protection unit. The operation command unit is connected to the safety control unit and is used to receive and transmit lifting, lowering, fast and slow operation commands. The power control and protection unit is connected to the main circuit of the hoisting motor and is used to limit the operating voltage and current, provide filtering and monitor the real-time current.

3. The system according to claim 2, characterized in that, It also includes an overload limiting unit, which is signal-connected to the power control and protection unit and the safety control unit. It is used to determine the overload state based on the real-time current and, when the overload is determined, to cut off the lifting control circuit of the lifting motor through the safety control unit.

4. The system according to claim 3, characterized in that, It also includes an emergency stop circuit unit, which includes an emergency stop button. When the emergency stop button is triggered, it can trip the main power switch to cut off the main power supply to the system. The emergency stop button also prevents the main power switch from being electrically reset before it is mechanically reset.

5. The system according to claim 3 or 4, characterized in that, It also includes a thermal overload relay and a time delay relay. The thermal overload relay is connected in series in the main circuit and control circuit of the hoisting motor. The time delay relay is connected in the down-moving control circuit of the hoisting motor and is used to output a reset signal to the overload limiting unit after the hoisting motor reaches a preset delay during the down-moving operation.

6. A safety protection and control method for a winch hoisting motor, applied to the system as described in any one of claims 1 to 5, characterized in that, include: Operation and control steps: Receive control commands and drive the hoisting motor and the hoisting drum to perform corresponding actions through the motor control unit; Temperature monitoring and protection steps: The temperature protection unit continuously monitors the internal temperature of the hoisting motor, and when the internal temperature exceeds a first set threshold, the motor overheat protection is executed, cutting off the control circuit of the hoisting motor.

7. The method according to claim 6, characterized in that, It also includes an overwind limit protection step: the limit protection unit monitors the rotation position of the hoisting drum, and when the hoisting drum is detected to have rotated to the overwind position, the limit switch is triggered to cut off the lifting control circuit of the hoisting motor.

8. The method according to claim 6, characterized in that, It also includes emergency stop and reset steps: when the emergency stop button is triggered, the main power switch is controlled to trip to cut off the main power supply to the system; when the system restarts, the emergency stop button must be mechanically reset before the main power switch can be electrically reset.

9. The method according to claim 6, characterized in that, It also includes overload protection and reset steps: the power control and protection unit monitors the real-time operating current of the hoisting motor; the overload limiting unit determines whether the load is overloaded; if overloaded, the hoisting control circuit of the hoisting motor is cut off and only descent operation is allowed; during the descent operation, the overload state is cleared by the time delay relay after a preset delay is reached.

10. The method according to claim 6, characterized in that, It also includes operation process and comprehensive monitoring steps: setting the start-up time parameter through the power control and protection unit, and protecting the system based on the parameter during the start-up phase; During operation, its filtering function is used to suppress sudden current changes, and thermal overload protection is provided through the thermal overload relay; at the same time, the power supply voltage and operating current are monitored in real time to comprehensively determine the working status of the hoisting motor.

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