A safety device for the operation of an indoor travelling crane of a ship unloader

Abstract

The present application relates to a kind of unloading machine indoor travelling crane car safety device, the safety device includes pulse incremental encoder, magnetic switch component, ultrasonic ranging sensor, proximity switch, audible and visual alarm, PLC device, indicating light and frequency converter, the pulse incremental encoder is installed on the motor output shaft of car, encoder signal is fed back to frequency converter, frequency converter is connected with the PLC device in the electrical room of crane equipment travelling crane, realizes speed and position closed-loop control;Magnetic switch component is used for the synchronous setting of travelling crane car and the precision deviation check of car position, this scheme can very conveniently realize the needs of the safety operation control process of multiple cranes and multiple port crane indoor travelling crane car, reduce field device configuration, can effectively meet the convenient needs of field equipment maintenance.

Description

Technical Field

[0001] This invention relates to a safety device, specifically a safety device for the operation of the overhead trolley in the interior of a ship unloader, belonging to the field of port logistics and transportation technology. Background Technology

[0002] Meigang Logistics Department's port has four wharves: the old system of the raw material wharf, the new system of the raw material wharf, Yunxiang Wharf, and the finished product wharf. Equipment includes gantry cranes, bridge grab unloaders, loading and unloading bridges, and bridge cranes. The bridge grab unloader (referred to as the unloader) and the indoor bridge crane (referred to as the crane) are installed in the machine room, mainly used for lifting objects during equipment maintenance and assisting in machine room maintenance operations, such as replacing the hoisting motor. An upstream stop device with a safety ruler is installed on the upstream stop device, and a limit switch is installed on the crane trolley. When the crane mechanism reaches the stop position, the safety ruler collidees with the crane's travel stop limit switch, cutting off the power to the crane motor and providing safety protection. Due to track and wheel misalignment during crane operation and significant inertia during braking, the crane may continue to travel a distance during high-speed braking due to inertia. This can easily damage the safety gauge and limit switches to varying degrees, leading to deformation and increased equipment downtime and maintenance costs. Common existing crane trolley stop control schemes for port cranes include: 1) Limit switches installed on the crane body, with a safety gauge at the stop end. The safety gauge triggers a stop signal, allowing the crane to stop freely due to inertia. However, this method is inconvenient for maintenance in case of malfunction; 2) No deceleration limit switches are used. The crane's stop limit switch is equivalent to an emergency stop. Sudden braking at full speed can cause damage to the crane's steel structure due to high inertia; 3) Infrared or laser sensors are used for deceleration, but are greatly affected by dust and the cleanliness of the reflectors; 4) Ground-based drone interfaces lack a medium for interaction and information exchange between the crane and operators, resulting in low visualization and the inability to directly read crane data; 5) Safety stop devices can be damaged when the crane wheels misalign, and the adjustability is poor. The maintenance of safety rulers takes a long time, and scaffolding is also required for high-altitude operations, so it is necessary to improve this situation. Summary of the Invention

[0003] This invention addresses the problems existing in the prior art by providing a safety device for the operation of the overhead trolley in a ship unloader. This technical solution improves upon existing safety devices by modifying the anti-collision ruler device and designing and manufacturing a new type of limit device. The position of the trolley is controlled by software, and the trolley automatically decelerates before reaching the stop limit, reducing the impact of the gantry crane's inertia and achieving a smooth stop. Furthermore, the safety ruler device is installed entirely on the trolley body, facilitating maintenance and thus achieving the goals of saving materials and protecting equipment.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: a safety device for the operation of the overhead trolley in a ship unloader's indoor equipment. The safety device includes a pulse incremental encoder, a magnetic switch assembly, an ultrasonic ranging sensor, a proximity switch, an audible and visual alarm, a PLC device, indicator lights, and a frequency converter. The pulse incremental encoder is installed on the output shaft of the trolley motor, and the encoder signal is fed back to the frequency converter. The frequency converter is connected to the PLC device inside the overhead trolley's electrical compartment to achieve closed-loop control of speed and position. The magnetic switch assembly is used for synchronous setting of the overhead trolley and accuracy deviation verification of the trolley's position. The ultrasonic ranging sensor is used to detect the position of the trolley and inputs it as a hardware deceleration signal to the PLC. The PLC program performs trolley speed deceleration control. The proximity switch, through an anti-collision device, provides a stop signal input for the trolley, protecting the trolley body. This solution provides a simple, convenient, and effective device. Through the pulse incremental encoder, magnetic switch, laser ranging sensor, proximity switch, and other devices, under the control of a programmable logic controller (PLC), it performs safe control of the trolley's operation according to a preset program, meeting the control requirements for safe operation of the overhead trolley in port crane indoor equipment. This solution can easily meet the safety operation control requirements of multiple cranes and multiple port cranes' indoor overhead cranes, reduce on-site equipment configuration, and effectively meet the on-site needs for convenient equipment maintenance.

[0005] As an improvement of this invention, the magnetic switch assembly is installed in the middle of the crane crossbeam. The magnetic switch assembly includes a magnetic switch and three magnetic blocks: magnetic block A, magnetic block B, and magnetic block C. These three inductive magnetic blocks are installed on the outside of the crane track. The magnetic switch engages and disengages its internal switch contacts through magnetic induction with the magnetic blocks. Magnetic block C16 is used for synchronizing the crane position to zero, while magnetic blocks A and B are used for multi-point deviation calibration of the crane position, resulting in more precise position control. The magnetic blocks are installed on the outside of the crane track for easy maintenance, without obstruction, and with no risk of high-altitude work.

[0006] As an improvement of the present invention, the anti-collision device includes a guide rod, a positioning groove, a positioning screw, a stop block, a sleeve, an anti-collision ruler, a limit switch, a spring, a fixing nut, an ultrasonic sensor, a stop post, and a stop plate. The guide rod is made of a cylindrical solid material, and the stop block is retained after machining on the left and right sides. The stop block is used to push and compress the spring. A positioning groove is machined into the lower left part of the guide rod for positioning the guide rod and preventing the guide rod from rotating inside the sleeve. The sleeve is a hollow rectangular cuboid, and a step is machined into the right side of the sleeve. The guide rod enters from the right side of the sleeve and presses against the stop block, and then the spring is pushed out from the right side of the sleeve. Slide the sleeve onto the guide rod, then screw the fixing nut into the inside of the right side of the sleeve and tighten it to limit the displacement of the spring. Machin a threaded hole in the lower left part of the sleeve, and screw on the positioning screw to limit the rotation of the guide rod. The anti-collision ruler is fixed to the guide rod with screws, and the limit is fixed to the sleeve with screws. The sleeve is fixed to the traveling trolley with screws. The ultrasonic sensor is installed on the traveling trolley, and the stop post is installed at the end of the trolley track. The ultrasonic sensor is used to detect the distance between the traveling trolley and the stop post. The stop plate is welded to the stop post, and the center of the stop plate is horizontal with the center of the guide rod for the stopping control of the traveling trolley.

[0007] As an improvement of the present invention, the audible and visual alarm is installed on both sides of the double boom beam of the crane for warning of the crane's operation; the indicator light is installed on one side of the double boom beam of the crane, with three LED lights (yellow, green, and red) that are constantly lit and flashing, for the operator to observe the crane's status, display the normal control status of the crane, indicate the loss of crane synchronization, and provide prompts for crane position deviation.

[0008] The ground is equipped with an industrial monitoring touch screen, which allows operators to check equipment status and fault displays on the touch screen computer screen, facilitating fault diagnosis and repair.

[0009] Compared with existing technologies, the present invention has the following advantages: 1) The technical solution makes full use of existing mature technologies such as sensor detection, mechanical transmission, and automatic software error reporting. With intelligent control as the goal and economy, practicality, safety and reliability as the premise, it solves the problems of high failure rate, poor operation control accuracy and inconvenient maintenance of indoor crane trolley limit devices, and improves the real-time performance and reliability of trolley operation control; 2) In this solution, the PLC device is the main component of crane automation control. In this technical solution, it is not necessary to add an independent PLC. The online PLCs used by each crane can be used, and the hardware redundancy of the original PLC is used for the wiring of control signal input and output. 1) A PLC control program is written to control the speed and position of the trolley, and the program is used to quickly verify the accuracy deviation of the trolley position and the endpoint stop position; 2) The trolley operation in this scheme is intelligently controlled, and an automatic real-time abnormal alarm is triggered when the trolley position deviation exceeds the set value, improving the trolley operation accuracy and safety; 3) The trolley control equipment is installed on the trolley body, which is convenient for maintenance and avoids the safety risks of working at height and the cost of erecting scaffolding; 4) Operators can check the equipment status and fault display through the touch screen computer screen, which is convenient for fault diagnosis. Operators can judge the trolley operation status of the trolley equipment through the function display of the on-site indicator lights; 5) PLC program control is adopted, and the trolley position is synchronized and quickly calibrated by writing program logic control. PLC program control is adopted, and the precise control of the trolley position is achieved by collecting pulse incremental encoder signals. Deceleration and endpoint stop are both achieved through hardware and software joint control. Attached Figure Description

[0010] Figure 1 Electrical control system diagram;

[0011] Figure 2 Cross-sectional view of the anti-collision device;

[0012] Figure 3 Left view of the anti-collision device;

[0013] Figure 4 Layout diagram of the mechanism at the endpoint;

[0014] Figure 5 Wheel position layout diagram;

[0015] Figure 6 Magnetic block layout diagram;

[0016] Figure 7 PLC logic control flowchart.

[0017] Description of the marked parts in the attached diagram:

[0018] 1. Guide rod; 2. Positioning groove; 3. Positioning screw; 4. Stop block; 5. Sleeve; 6. Anti-collision ruler; 7. Limit switch; 8. Spring; 9. Fixing nut; 10. Ultrasonic sensor; 11. Stop post; 12. Stop plate; 13. Trolley track; 14. Magnetic switch; 15. Trolley; 16. Magnetic block C; 17. Trolley motor; 18. Pulse incremental encoder; 19. Magnetic block A; 20. Magnetic block B; 21. Indicator light; 22. Audible and visual alarm. Detailed implementation method:

[0019] To enhance understanding of the present invention, the embodiments will be described in detail below with reference to the accompanying drawings.

[0020] Example 1: See Figures 1-7A safety device for the operation of the overhead trolley in a ship unloader's indoor equipment is disclosed. The device includes a pulse incremental encoder, a magnetic switch assembly, an ultrasonic ranging sensor, a proximity switch, an audible and visual alarm, a PLC, indicator lights, and a frequency converter. The pulse incremental encoder is mounted on the output shaft of the trolley motor, and the encoder signal is fed back to the frequency converter. The frequency converter is connected to the PLC inside the crane's electrical room to achieve closed-loop control of speed and position. The magnetic switch assembly is used for synchronous setting of the trolley and for verifying the accuracy deviation of the trolley's position. The ultrasonic ranging sensor detects the trolley's position and inputs it as a hardware deceleration signal to the PLC, which then controls the trolley's speed deceleration. The proximity switch, through an anti-collision device, provides a stop signal input for the trolley, protecting the trolley body. This solution provides a simple, easy-to-operate, and effective control device. Through the pulse incremental encoder, magnetic switch, ultrasonic ranging sensor, proximity switch, and other equipment, under the control of a programmable logic controller (PLC), it performs safe control of the trolley's operation according to a preset program, meeting the control requirements for safe operation of the overhead trolley in port crane indoor equipment. Due to its structural features, this technology can easily meet the safety operation control needs of multiple cranes and port cranes operating indoors, reducing on-site equipment configuration and effectively satisfying the need for convenient on-site equipment maintenance. The magnetic switch assembly is installed in the middle of the crane crossbeam. The assembly includes a magnetic switch 14 and three magnetic blocks: magnetic block A19, magnetic block B20, and magnetic block C16. These three inductive magnetic blocks are installed on the outside of the crane rail. The magnetic switch uses magnetic induction with the magnetic blocks to activate and deactivate its internal switch contacts. Magnetic block C16 is used for synchronizing the crane position to zero, while magnetic blocks A19 and B20 are used for multi-point deviation calibration of the crane position, resulting in more precise position control. The magnetic blocks are installed on the outside of the crane rail 13 for easy maintenance, without obstruction, and with no risk of high-altitude operations.The anti-collision device includes a guide rod 1, a positioning groove 2, a positioning screw 3, a stop block 4, a sleeve 5, an anti-collision ruler 6, a limit switch 7, a spring 8, a fixing nut 9, an ultrasonic sensor 10, a stop post 11, and a stop plate 12. The guide rod 1 is made of a cylindrical solid material. After processing on the left and right sides, the stop block 4 is retained. The stop block 4 is used to push and compress the spring 8. The lower left part of the guide rod 1 is machined to form a positioning groove 2 for positioning the guide rod 1 and preventing the guide rod 1 from rotating inside the sleeve. The sleeve 5 is a hollow rectangular cuboid with a step machined on the right side. The guide rod 1 enters from the right side of the sleeve 5 and presses against the stop block 4. Then, the spring 8 is inserted from the right side of the sleeve 5 onto the guide rod 1. Next, screw the fixing nut 9 into the inside of the right side of the sleeve 5 and tighten it to limit the displacement of the spring 8. Machin a threaded hole in the lower left part of the sleeve 5 and screw on the positioning screw 3 to limit the rotation of the guide rod 1. The anti-collision ruler 6 is fixed to the guide rod 1 with screws. The limit 7 is fixed to the sleeve 5 with screws. The sleeve is fixed to the traveling trolley with screws. The ultrasonic sensor 10 is installed on the traveling trolley 15. The stop post 11 is installed at the end of the trolley track 13. The ultrasonic sensor 10 is used to detect the distance between the traveling trolley 15 and the stop post 11. The stop plate 12 is welded to the stop post 11. The center of the stop plate 12 is horizontal with the center of the guide rod 1 and is used for stopping control of the traveling trolley 15.

[0021] The audible and visual alarms are installed on both sides of the crane's double boom beams to warn of crane movement. The indicator lights, each with three LEDs (yellow, green, and red), are installed on one side of the crane's double boom beams, providing both constant illumination and flashing illumination for operators to observe the crane's status, displaying normal crane control status, indicating crane synchronization loss, and alerting to crane position deviation. An industrial monitoring touchscreen is installed on the ground, allowing operators to view equipment status and fault displays via the touchscreen computer screen, facilitating troubleshooting.

[0022] Work process: Refer to Figure 1 — Figure 7 The working process of the anti-collision device is as follows: When the crane 15 moves towards the machine room, the audible and visual alarm 22 is energized to issue a safety warning. The PLC performs proactive deceleration control in advance based on the position feedback from the encoder 18, and the crane motor 17 decelerates according to the drive signal from the frequency converter. When the ultrasonic sensor 10 detects the stop block 11, it outputs a signal to the PLC, and the PLC performs program control to decelerate again. When the crane 15 decelerates to the stop plate 12, the guide rod 1 is forced to move in the opposite direction. The guide rod 1 is restricted by the positioning groove 2 and the positioning screw 3 to prevent rolling deviation. The stop block 4 pushes the spring 8 to compress, and the anti-collision ruler 6 moves together with the guide rod 1 to collide with the transmission head of the limit switch 7. The limit switch 7 gives an end limit signal to the PLC, and the crane 15 brakes to stop. The spring 8 absorbs the inertia of the crane 15. If the limit switch 7 is abnormal and cannot give a normal signal, the PLC will perform software limit position stop control based on the position feedback from the pulse incremental encoder 18.

[0023] The working process of synchronizing the main vehicle is as follows: See Figure 2 — Figure 7 An incremental pulse encoder 18, mounted on the trolley motor 17, is hardwired to the frequency converter for speed and position feedback of the trolley motor 17. The pulse count is converted into actual position (meters) for position display, software deceleration, stop limit, and all motion positioning. The actual position value is stored in the PLC controller's register, which is continuously updated based on the position value received from the frequency converter driver. The driver's position memory can be synchronized via a hardware synchronization signal emitted by the magnetic switch 14 connected to the driver. The conditions for trolley synchronization are: the operator uses the control box or remote control to set the trolley synchronization; the knob switches from the trolley normal mode to the synchronization adjustment mode; the trolley 15 travels from upstream to downstream (from magnetic block 19 to magnetic block 20) ​​past magnetic block C16; and the magnetic switch 14's contact changes from "0" to "1" when synchronization occurs. During trolley synchronization, the value in the driver's position memory is cleared, and the corresponding pre-set synchronization position value in the trolley PLC, i.e., the actual position value of the magnetic switch 14, is stored in the frequency converter driver. Synchronization is only required when there is no synchronization, such as when there is a fault in pulse incremental encoder 18, a fault in magnetic switch 14, software detection of position deviation, or power failure of the vehicle.

[0024] The working process of large vehicle deviation verification: see Figure 1 , Figure 4 , Figure 5 , Figure 6 , Figure 7 The overhead crane 15 operates normally with the main trolley already synchronized. Position detection and deviation verification are performed when it passes the deceleration limit ultrasonic sensor 10, the synchronization limit point magnetic block C16, and the position detection point magnetic blocks A19 and B20. The PLC of the overhead crane 15 compares the actual position value with the preset physical values ​​of these detection points. If the deviation exceeds the set allowable value, the main trolley motor 17 of the overhead crane 15 will be speed-limited, and the corresponding fault information will be reported on the ground industrial monitoring touchscreen. After the position deviation, the main trolley of the overhead crane 15 needs to re-synchronize.

[0025] The working process of the light assembly: see Figure 1 , Figure 6 , Figure 7 Indicator light 21 consists of three LEDs, which are yellow, green, and red in sequence. The green light indicates that the trolley control is normal, the yellow light indicates that the trolley position is not synchronized, the yellow light flashes when the trolley position is off, and the red light indicates that the trolley is faulty. This allows operators and maintenance personnel to have a clear understanding of the trolley status of the trolley.

[0026] The technology of this invention has been experimentally applied to the indoor overhead crane of the port bridge grab unloader at Meigang Transportation Department, achieving good results. It has improved operational efficiency and reduced equipment maintenance costs. In the context of increasingly busy production operations, this intelligent technical solution enables intelligent equipment detection, effectively controlling equipment stability and keeping the equipment failure rate at a low level, which is of great significance to the company's production.

[0027] It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention. Equivalent transformations or substitutions made based on the above technical solutions all fall within the scope of protection of the claims of the present invention.

Claims

1. A safety device for the operation of the overhead trolley in the interior of a ship unloader, characterized in that, The safety device includes a pulse incremental encoder, a magnetic switch assembly, an ultrasonic ranging sensor, a proximity switch, an audible and visual alarm, a PLC device, indicator lights, and a frequency converter. The pulse incremental encoder is installed on the output shaft of the trolley motor, and the encoder signal is fed back to the frequency converter in the trolley electrical control cabinet. The frequency converter is connected to the PLC device inside the crane's electrical room to realize closed-loop control of speed and position. The magnetic switch assembly is used for the synchronization setting of the trolley and the accuracy deviation verification of the trolley position. The ultrasonic ranging sensor is used to detect the position of the trolley and inputs it as a hardware deceleration signal to the PLC. The PLC program performs trolley speed deceleration control. The proximity switch realizes the trolley stop signal input through an anti-collision device to protect the trolley body. The magnetic switch assembly is installed in the middle of the crane crossbeam. The magnetic switch assembly includes a magnetic switch (14) and three magnetic blocks, namely magnetic block A (19), magnetic block B (20) and magnetic block C (16). The three sensing magnetic blocks are installed on the outside of the crane track. The anti-collision device includes a guide rod, a positioning groove, a positioning screw, a stop block, a sleeve, an anti-collision ruler, a limit switch, a spring, a fixing nut, an ultrasonic sensor, a stop post, and a stop plate. The guide rod is made of a cylindrical solid material, with the stop block retained after machining on the left and right sides. The stop block is used to push and compress the spring. A positioning groove is machined into the lower left part of the guide rod for positioning the guide rod and preventing it from rotating inside the sleeve. The sleeve is a hollow rectangular cuboid, with a step machined into the right side. The guide rod enters from the right side of the sleeve and presses against the stop block. Then, the spring is inserted into the guide rod from the inside of the right side of the sleeve. Next, screw the fixing nut into the inside of the right side of the sleeve and tighten it to limit the displacement of the spring. Machin a threaded hole in the lower left part of the sleeve and screw on the positioning screw to limit the rotation of the guide rod. The anti-collision ruler is fixed to the guide rod with screws, and the limit is fixed to the sleeve with screws. The sleeve is fixed to the traveling trolley with screws. The ultrasonic sensor is installed on the traveling trolley, and the stop post is installed at the end of the trolley track. The ultrasonic sensor is used to detect the distance between the traveling trolley and the stop post. The stop plate is welded to the stop post. The center of the stop plate is horizontal with the center of the guide rod and is used for the stopping control of the traveling trolley. The audible and visual alarm is installed on both sides of the double boom beam of the crane for warning of the crane's operation; the indicator light is installed on one side of the double boom beam of the crane, with three LED lights (yellow, green, and red) that are constantly lit and flashing, for the operator to observe the crane's status, display the normal control status of the crane, indicate the loss of crane synchronization, and provide prompts for crane position deviation. The ground is equipped with an industrial monitoring touch screen, allowing operators to check equipment status and fault displays via the touch screen computer screen.

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