A device and method for safety interlocking of roller conveyor and overhead crane

Abstract

This invention relates to a device and method for safety interlocking between a roller conveyor and an overhead crane. The device includes an coded cable address detector, a redundant cold-detection positioning sensor, an overhead crane weighing device, a height encoder, an overhead crane PLC system, a roller conveyor PLC system, onboard wireless WIFI, ground wireless WIFI, and a roller conveyor drive system. The aforementioned coded cable address detector and redundant cold-detection positioning sensor, combined with logic calculation, form a stopping interlock for the roller conveyor. The overhead crane weighing device and height encoder, combined with logic calculation, form a roller conveyor interlock release command, realizing a safety interlock between the billet conveying roller conveyor and the billet hoisting overhead crane, while greatly improving the conveying efficiency of the roller conveyor.

Description

Technical Field

[0001] This patent application belongs to the field of steel production equipment technology, and more specifically, relates to a device and method for safety interlocking of roller conveyors and overhead cranes. Background Technology

[0002] In today's metallurgical industry, continuous casting and hot rolling mills have long been integrated with their conveyor rollers, enabling hot conveying. Hardware and software systems such as overhead crane positioning, slab tracking, and slab management are also well-established, providing a solid foundation for improved production efficiency. However, with increasingly stringent production efficiency and hot conveying efficiency targets, the manual operation of slab removal significantly hinders production pace. In practice, operators frequently have to manually stop the conveyor rollers, wasting considerable time. Besides low production efficiency, these operations also pose serious safety hazards, with instances of roller rotation during slab lifting damaging overhead crane drums and wire ropes. This severely hinders high-efficiency production, necessitating a solution to address this issue. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a device and method for safety interlocking of roller conveyors and overhead cranes, which has the characteristics of wide application, safety and accuracy, and can solve the efficiency constraints and safety hazards caused by manual operation of overhead cranes.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0005] A safety interlock device for roller conveyor and overhead crane includes a roller conveyor system and an overhead crane system. The roller conveyor system includes a ground roller conveyor PLC system, redundant cold detection positioning sensors, ground wireless WIFI, and roller conveyor drive system. The redundant cold detection positioning sensors, ground wireless WIFI, and roller conveyor drive system are all connected to the ground roller conveyor PLC system.

[0006] The overhead crane system includes an overhead crane PLC system, an coded cable address detector, an overhead crane weighing device, a height encoder, and onboard wireless WIFI. The coded cable address detector, the overhead crane weighing device, the height encoder, and the onboard wireless WIFI are all connected to the overhead crane PLC system.

[0007] The coded cable address detector is installed on one side of the crane and is connected to the coded cable under the crane. It is used for continuous positioning of the crane and can detect the continuous position of the crane.

[0008] Two redundant cold-detection positioning sensors are installed on the overhead crane walkway to directly detect the overhead crane's switch position signal (i.e., to detect whether the overhead crane is in position).

[0009] The crane weighing device is installed below the wire rope drum at the crane hook and is used to measure the weight of the slab carried by the crane clamp.

[0010] A height encoder is coaxially mounted behind the wire rope drum drive motor and is used to calculate the height of the overhead crane clamp.

[0011] The overhead crane PLC system is used to collect signals from the sensors on the overhead crane and process and calculate these signals.

[0012] The ground roller conveyor PLC system is used to collect signals from ground sensors;

[0013] The vehicle-mounted wireless WIFI and the ground wireless WIFI are connected for signal interaction between the ground roller conveyor PLC system and the overhead crane PLC system.

[0014] Roller conveyor systems are used to directly control the operation of roller conveyors.

[0015] Furthermore, the redundant cold detection positioning sensors are cold metal detectors, which are respectively arranged on the left and right sides of the ground roller conveyor.

[0016] Furthermore, the crane weighing device is a crane weighing instrument, and the height encoder is a drum encoder.

[0017] A method for safety interlocking of roller conveyors and overhead cranes, utilizing the aforementioned device, includes the following steps:

[0018] Step S1: Set up the device and get it ready. Name the two redundant cold metal detectors as Cold Metal Detector No. 1 and Cold Metal Detector No. 2, respectively.

[0019] Step S2: The coded cable address detector and redundant cold metal detection positioning sensor perform real-time detection. The onboard and ground-based wireless Wi-Fi signals interact in real-time. When the coded cable address detector detects that the overhead crane is directly above the roller conveyor, and both cold metal detectors (No. 1 and No. 2) show signals (these two detectors are not merely redundant; their positions on the left and right sides of the roller conveyor ensure accurate detection of the overhead crane being above the ground roller conveyor), and the ground roller conveyor is in automatic mode, the ground roller conveyor PLC system controls the roller conveyor drive system, which in turn stops the ground roller conveyor, triggering the interlock. The different types of sensors provide dual protection for the equipment, effectively preventing equipment accidents caused by a single sensor failure, and significantly improving the effectiveness of the interlock. After the interlock takes effect, the ground roller conveyor no longer executes the forward movement requirement according to the original logic until the interlock is released.

[0020] Step S3: The overhead crane PLC system controls the descent of the overhead crane clamp to begin lifting the slab. Simultaneously, the weight of the slab carried by the clamp is tracked by the overhead crane weighing device. A correlation exists between the clamp height and the slab weight. When the overhead crane clamp lifts the slab, the lifting position is between -1350mm and -950mm. The relationship between the clamp height and the slab weight is non-linear, as shown in the table below:

[0021]

[0022] When the current position is reached, an alarm will be triggered if the weight deviation of the slab exceeds 10%, and the current interlock cannot be deactivated. At the same time, the accuracy of each corresponding sensor can be verified through the relationship table. If there are frequent alarms, the corresponding sensor should be checked or replaced, which greatly improves the effectiveness of the interlock.

[0023] Step S4: The overhead crane PLC system controls the overhead crane clamp to begin rising, and the weight of the slab carried by the overhead crane clamp changes. At approximately 0m, the overhead crane weighing device begins to stabilize, thus establishing a verification model: At the current position, while the deviation of the overhead crane weighing device meets the above verification model, it is also necessary to keep its weight stable at the position between 60mm and 140mm, and any position between 60mm and 140mm is less than 5% of the average of the 5 positions; at this time, it is determined that the slab has left the ground roller conveyor, but the system still increases the safety distance. After determining that the slab has left the roller conveyor, it still rises h meters as a safety distance.

[0024] Step S5: As the crane clamp continues to rise, when the height encoder detects that the rising height of the crane clamp is greater than the safe distance h meters and the weight of the slab detected by the crane weighing device is greater than 85% of the weight of the slab, the interlock of stopping the ground track is released.

[0025] Step S6: The interlock release signal is issued, and a start pulse is sent to the ground roller conveyor. When the coded cable address detector does not detect that the crane position is directly above the roller conveyor, and both cold metal detectors No. 1 and No. 2 have no signal, the ground roller conveyor is released from the interlock and starts running.

[0026] Furthermore, in step S4, h = 1 to 2, with an ascent of 1 to 2 meters as a safety distance.

[0027] Due to the adoption of the above technical solution, the beneficial effects achieved by this invention are:

[0028] This invention achieves full automation without the need for ground operators to operate or confirm, and ensures reliability through two sets of safety interlocking devices.

[0029] This invention can redundantly achieve safety interlocking between the overhead crane and the roller conveyor, and the hardware belongs to different detection types, which has high effectiveness and error prevention; it realizes the full automation of the roller conveyor operation, which can greatly reduce the impact of overhead crane hoisting on the roller conveyor operation, improve production efficiency, and has high efficiency.

[0030] In this invention, the effective ground roller conveyor interlock utilizes the continuous crane position detected by the coded cable address detector and the crane switch position signal detected by the redundant cold-detection positioning sensor. The ineffective ground roller conveyor interlock utilizes the slab weight measured by the crane weighing device and the crane fixture height measured by the height encoder. These different types of sensors provide dual protection for the equipment, effectively preventing equipment accidents caused by a single sensor failure, thus significantly improving the interlock effectiveness.

[0031] This invention achieves fully automated operation of the ground roller conveyor. During smooth production, the ground roller conveyor is completely automatic, reducing the number of operators required. Simultaneously, through experimentation, the optimal timing for interlock release was determined, maximizing the operating efficiency of the ground roller conveyor and eliminating any limiting factors on productivity improvement. This significantly enhances production efficiency and demonstrates high performance.

[0032] This invention features full automation, significantly reducing operator workload; high efficiency, with optimized start-up time from ground roller conveyor stop, greatly increasing production efficiency; and safety and reliability, with redundant interlocking control to prevent equipment accidents. Attached Figure Description

[0033] Figure 1 This is a control system diagram of the device of the present invention.

[0034] Figure 2 This is a system functional flowchart of the method of the present invention.

[0035] Among them: 1. Encoded cable address detector; 2. Redundant cold detection positioning sensor; 3. Overhead crane weighing device; 4. Height encoder; 5. Overhead crane PLC system; 6. Ground roller conveyor PLC system; 7. Onboard wireless WIFI; 8. Ground wireless WIFI; 9. Roller conveyor transmission system. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to the embodiments.

[0037] A safety interlock device between a roller conveyor and an overhead crane, such as Figure 1 As shown: It includes a roller conveyor system and a crane system. The roller conveyor system includes a ground roller conveyor PLC system 6, a redundant cold inspection positioning sensor 2, a ground wireless WIFI 8, and a roller conveyor transmission system 9. The redundant cold inspection positioning sensor 2, the ground wireless WIFI 8, and the roller conveyor transmission system 9 are all connected to the ground roller conveyor PLC system 6.

[0038] The overhead crane system includes an overhead crane PLC system 5, an coded cable address detector 1, an overhead crane weighing device 3, a height encoder 4, and an onboard wireless WIFI 7. The coded cable address detector 1, the overhead crane weighing device 3, the height encoder 4, and the onboard wireless WIFI 7 are all connected to the overhead crane PLC system 5.

[0039] The coded cable address detector 1 is installed on one side of the crane and is connected to the coded cable under the crane. It is used for continuous positioning of the crane and can detect the continuous position of the crane.

[0040] Redundant cold detection positioning sensors 2 are installed on the overhead crane walkway. They are used to directly detect the overhead crane switch position signal (that is, to detect whether the overhead crane is in position). There are 2 of them.

[0041] The crane weighing device 3 is installed below the wire rope drum at the crane hook and is used to measure the weight of the slab carried by the crane clamp.

[0042] The height encoder 4 is coaxially mounted behind the wire rope drum drive motor and is used to calculate the height of the crane clamp.

[0043] The overhead crane PLC system 5 is used to collect signals from the sensors on the overhead crane and process and calculate these signals.

[0044] The ground roller conveyor PLC system 6 is used to collect signals from ground sensors;

[0045] The vehicle-mounted wireless WIFI7 and the ground-based wireless WIFI8 are connected for signal interaction between the ground roller conveyor PLC system 6 and the overhead crane PLC system 5.

[0046] The roller conveyor system 9 is used to directly control the operation of the roller conveyor.

[0047] In terms of selection, the redundant cold detection positioning sensor 2 is a cold metal detector, which is arranged on the left and right sides of the ground roller conveyor respectively; the crane weighing device 3 is a crane weighing instrument, and the height encoder 4 is a drum encoder.

[0048] The interlocking method of the above-mentioned device is as follows:

[0049] Step S1: Set up the device and get it in place. Name the two redundant cold detection positioning sensors 2 as Cold Metal Detector No. 1 and Cold Metal Detector No. 2, respectively.

[0050] Step S2: The coded cable address detector 1 and redundant cold metal detection positioning sensor 2 perform real-time detection. The onboard Wi-Fi 7 and ground Wi-Fi 8 interact in real-time. When the coded cable address detector 1 detects that the overhead crane is directly above the roller conveyor, and both cold metal detectors 1 and 2 have signals (the two redundant cold metal detection positioning sensors 2 are not merely redundantly arranged; their positions on the left and right sides of the roller conveyor ensure accurate detection of the overhead crane being above the ground roller conveyor), and the ground roller conveyor is in automatic mode, the ground roller conveyor PLC system 6 controls the roller conveyor drive system 9, which in turn stops the ground roller conveyor, triggering the interlock. Different types of sensors provide dual protection for the equipment, effectively preventing equipment accidents caused by a single sensor failure, and significantly improving the effectiveness of the interlock. After the interlock takes effect, the ground roller conveyor no longer executes the forward operation requirement according to the original logic until the interlock is released.

[0051] Step S3: The overhead crane PLC system 5 controls the descent of the overhead crane clamp to begin lifting the slab. Simultaneously, the weight of the slab carried by the overhead crane clamp is tracked by the overhead crane weighing device 3. A corresponding relationship is established between the clamp height and the slab weight. When the overhead crane clamp lifts the slab, the lifting position is between -1350mm and -950mm. The height of the overhead crane clamp and the slab weight exhibit a non-linear relationship, as shown in the table below:

[0052]

[0053] When the current position is reached, an alarm will be triggered if the weight deviation of the slab exceeds 10%, and the current interlock cannot be deactivated. At the same time, the accuracy of each corresponding sensor can be verified through the relationship table. If there are frequent alarms, the corresponding sensor should be checked or replaced, which greatly improves the effectiveness of the interlock.

[0054] Step S4: The overhead crane PLC system 5 controls the overhead crane clamp to begin rising, and the weight of the slab carried by the overhead crane clamp changes. At approximately 0m, the overhead crane weighing device 3 begins to stabilize, thus establishing a verification model:

[0055]

[0056] At the current position, while the deviation of the overhead crane weighing device 3 meets the above verification model, it is also necessary to keep its weight stable at the position between 60mm and 140mm, and any position between 60mm and 140mm is less than 5% of the average of the 5 positions; at this time, it is determined that the slab has left the ground roller conveyor, but the system still increases the safety distance. After determining that the slab has left the roller conveyor, it still rises by h meters as a safety distance; h = 1~2, rising by 1~2 meters as a safety distance.

[0057] Step S5: As the crane clamp continues to rise, when the height encoder 4 detects that the rising height of the crane clamp is greater than the safe distance h meters and the weight of the slab detected by the crane weighing device 3 is greater than 85% of the weight of the slab, the interlock of stopping the ground track is released.

[0058] Step S6: The interlock release signal is issued, and a start pulse is sent to the ground roller conveyor. When the coded cable address detector 1 does not detect that the crane position is directly above the roller conveyor, and both the No. 1 cold metal detector and the No. 2 cold metal detector have no signal, the ground roller conveyor is released from the interlock and starts running.

[0059] The following description is based on an example.

[0060] like Figure 1 The overhead crane weighing device 3 is installed below the wire rope drum of the overhead crane hook to detect the weight of the slab carried by the overhead crane clamp; the height encoder 4 is coaxially installed behind the drive motor of the wire rope drum to calculate the height of the overhead crane clamp; the coded cable address detector 1 is installed on one side of the overhead crane and works with the coded cable installed under the crane to continuously position the crane; the redundant cold detection positioning sensor 2 is installed on the crane platform to directly detect whether the crane is in position. The overhead crane PLC system 5 is used to collect and calculate the signals from the sensors on the crane; the roller conveyor PLC system 6 is used to collect the signals from the ground sensors; the on-board wireless WIFI 7 and the ground wireless WIFI 8 are used for signal interaction between the overhead crane and the roller conveyor PLC; the roller conveyor transmission system 9 is used to directly control the operation of the roller conveyor.

[0061] Methods such as Figure 2 The functional flowchart shown includes the following steps:

[0062] Step 1: Encoded cable address detector 1 detects that the overhead crane is directly above the ground roller conveyor. Simultaneously, cold metal detectors 1 and 2 both show signals (the two redundant cold metal detection sensors 2 are not merely redundantly arranged; their positions on the left and right sides of the ground roller conveyor ensure accurate detection of the overhead crane being above it). When the ground roller conveyor is in automatic mode, the interlock activates. These different types of sensors provide dual protection for the equipment, effectively preventing equipment accidents caused by a single sensor failure, and significantly improving the effectiveness of the interlock. After the interlock activates, the roller conveyor no longer executes the forward movement requirement according to the original logic until the interlock is released.

[0063] Step 2: The overhead crane begins lifting the slab, and the clamps descend. Simultaneously, the weight of the clamps is tracked, establishing a correlation between clamp height and weight changes, thus verifying the accuracy of the sensors. This cross-verification between different sensors significantly improves the effectiveness of the interlocking system.

[0064] Step 3: The overhead crane clamps begin to rise, and the weight of the clamps also changes. Based on the mutually corroborating models, it is determined that the slab has left the ground roller conveyor. However, the system still increases the safety distance. After determining that the slab has left the roller conveyor, it still rises by 1 meter as a safety distance.

[0065] Step 4: The overhead crane clamp continues to rise. Once it exceeds the safe distance, the interlock is released. The signal to release the interlock is also sent as a start pulse. The roller conveyor will start automatically when permitted.

[0066] The coded cable address detector 1 and redundant cold detection positioning sensor 2 of this invention combine logic calculation to form a parking interlock for the roller conveyor. The crane weighing device 3 and height encoder 4 combine logic calculation (for example, if the weight of the slab measured by the crane weighing device 3 is greater than 85% of the weight of the slab, and at the same time the height encoder 4 of the crane clamp measures a clamp height that is greater than 1m from the roller conveyor, i.e., an interlock release signal is generated) to form a roller conveyor interlock release command. This realizes the safety interlock between the billet conveying roller conveyor and the billet hoisting crane, and at the same time greatly improves the conveying efficiency of the roller conveyor.

[0067] This invention achieves fully automated operation of the ground roller conveyor. During smooth production, the ground roller conveyor is completely automatic, reducing the number of operators required for its operation. Furthermore, through extensive experimentation, the optimal timing for interlock release was determined, maximizing the operating efficiency of the ground roller conveyor and eliminating any bottlenecks in productivity improvement caused by its operation. This significantly enhances production efficiency and demonstrates high performance.

Claims

1. A device for safety interlocking roller conveyors and overhead cranes, characterized in that: It includes a roller conveyor system and a crane system. The roller conveyor system includes a ground roller conveyor PLC system (6), a redundant cold detection positioning sensor (2), a ground wireless WIFI (8), and a roller conveyor transmission system (9). The redundant cold detection positioning sensor (2), the ground wireless WIFI (8), and the roller conveyor transmission system (9) are all connected to the ground roller conveyor PLC system (6). The overhead crane system includes an overhead crane PLC system (5), an coded cable address detector (1), an overhead crane weighing device (3), a height encoder (4), and an onboard wireless WIFI (7). The coded cable address detector (1), the overhead crane weighing device (3), the height encoder (4), and the onboard wireless WIFI (7) are all connected to the overhead crane PLC system (5). The coded cable address detector (1) is installed on one side of the crane and is connected to the coded cable under the crane. It is used for continuous positioning of the crane and can detect the continuous position of the crane. Two redundant cold detection positioning sensors (2) are installed on the overhead crane platform to directly detect the overhead crane switch position signal. The crane weighing device (3) is installed below the wire rope drum at the crane hook and is used to measure the weight of the slab carried by the crane clamp. The height encoder (4) is coaxially mounted to the rear of the wire rope drum drive motor and is used to calculate the height of the crane clamp; the crane PLC system (5) is used to collect the signals from the sensors on the crane and process and calculate the above signals; The ground roller conveyor PLC system (6) is used to collect ground sensor signals; The vehicle-mounted wireless WIFI (7) and the ground wireless WIFI (8) are connected for signal interaction between the ground roller conveyor PLC system (6) and the overhead crane PLC system (5); The roller conveyor system (9) is used to directly control the operation of the roller conveyor; The height of the overhead crane fixture varies non-linearly with the weight of the slab, as shown in the table below: ； At position 0m, the crane weighing device (3) begins to stabilize, thus establishing a verification model: 。 2. The device for safety interlocking roller conveyor and overhead crane according to claim 1, characterized in that: The redundant cold detection positioning sensor (2) is a cold metal detector, which is arranged on the left and right sides of the ground roller conveyor.

3. The device for safety interlocking of roller conveyor and overhead crane according to claim 2, characterized in that: The overhead crane weighing device (3) is an overhead crane weighing instrument, and the height encoder (4) is a drum encoder.

4. A method for safety interlocking of roller conveyors and overhead cranes, utilizing the device described in claim 1, characterized in that... Includes the following steps: Step S1: Set up the device and prepare it in place. Name the two redundant cold detection positioning sensors (2) as No. 1 cold metal detector and No. 2 cold metal detector, respectively. Step S2: The coded cable address detector (1) and redundant cold detection positioning sensor (2) are detected in real time. The on-board wireless WIFI (7) and the ground wireless WIFI (8) interact in real time. When the coded cable address detector (1) detects that the crane is directly above the roller conveyor, and at the same time, the No. 1 cold metal detector and the No. 2 cold metal detector have signals, the two cold metal detectors are not only redundantly arranged, but their positions are arranged on the left and right sides of the roller conveyor, which can accurately detect that the crane is above the ground roller conveyor. At the same time, when the ground roller conveyor is in automatic mode, the ground roller conveyor PLC system (6) controls the roller conveyor transmission system (9), and the roller conveyor transmission system (9) controls the ground roller conveyor to stop, and the interlock takes effect. Step S3: The overhead crane PLC system (5) controls the overhead crane clamp to descend and starts to lift the slab. While the overhead crane clamp is descending, the weight of the slab carried by the overhead crane clamp is tracked by the overhead crane weighing device (3). The clamp height and the change in slab weight form a corresponding relationship. When the overhead crane clamp carries the slab to rise, the rising position is between -1350mm and -950mm. When in the current position, if the deviation of the slab weight is greater than 10%, an alarm will be generated, and the current interlock cannot be released. At the same time, the accuracy of each corresponding sensor can be verified through this relationship table. If there are frequent alarms, the corresponding sensor should be checked or replaced. Step S4: The overhead crane PLC system (5) controls the overhead crane clamp to start rising. The weight of the slab carried by the overhead crane clamp changes. At the current position, the deviation of the overhead crane weighing device (3) satisfies the above verification model. At the same time, it is necessary to keep its weight stable at the position from 60mm to 140mm. And any position from 60mm to 140mm is less than 5% of the average of the 5 positions. At this time, it is judged that the slab has left the ground roller. After the slab leaves the roller, it still rises h meters as a safety distance. Step S5: As the crane clamp continues to rise, when the height encoder (4) detects that the rising height of the crane clamp is greater than the safe distance h meters and the weight of the slab detected by the crane weighing device (3) is greater than 85% of the weight of the slab, the interlocking of the ground track stopping is released. Step S6: The interlock release signal is issued, and a start pulse is sent to the ground roller conveyor. When the coded cable address detector (1) does not detect that the crane position is directly above the roller conveyor, and when both the No. 1 cold metal detector and the No. 2 cold metal detector have no signal, the ground roller conveyor is released from the interlock and starts running.

5. A method for safety interlocking of roller conveyors and overhead cranes according to claim 4, characterized in that: In step S4, h = 1~2, and the ascent is 1~2 meters as a safety distance.

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