Information transmission device for improving detection precision of metallurgical casting travelling crane and crown block scale

Abstract

An information transmission device for improving the detection precision of a metallurgical casting travelling crane and crown block scale comprises two groups of fixed pulley blocks and a secondary instrument, a connecting shaft body is installed in the two groups of fixed pulley blocks, weighing sensors are installed at the positions, close to the lower end of the connecting shaft body, of the two ends of the two groups of fixed pulley blocks, and elastic modulus compensation pieces are installed in the four weighing sensors. And the four weighing sensors are electrically connected with the secondary instrument. The beneficial effects are that the device can greatly improve system precision, can adapt to severe working conditions such as high temperature and high dust, molten iron splashing, steel ladle hoisting and the like, can realize standardization of a signal transmission mode, realizes spare part exchange with other crown block scales, stabilizes a power supply of a secondary instrument, does not lose internal parameters, and is convenient to use. The device is simple in structure, is not influenced by voltage drop or power tripping, can operate safely and stably for a long time, and is additionally provided with a transmitting output circuit unit and an RS232 communication circuit unit, so that PLC signals can be continuously and stably transmitted to the converter in an all-weather manner, and a fair and just basis is provided for counting molten iron consumption per shift.

Description

Technical Field

[0001] This utility model relates to an information transmission device, specifically an information transmission device for improving the detection accuracy of overhead crane scales in metallurgical casting. Background Technology

[0002] The metallurgical casting overhead crane weighing system consists of two fixed pulley weighing frames, resistance strain gauge load cells, wire rope compensators, an intelligent weight display transmitter limiter (secondary instrument), a wireless data transmission weighing receiver display, a large display, an industrial control computer display, and an audible and visual alarm. The intelligent weight display transmitter limiter (secondary instrument) integrates weighing display, overload limitation, and weight signal transmission, and is designed for use in harsh environments, areas with severe power fluctuations, and unmanned operation. It works in conjunction with the wireless data transmission weighing receiver display to receive serial weighing data from the secondary instrument, display it, and connect to the host computer. The operation methods of the transmitter and receiver instruments are identical; when used together, the parameter settings are consistent, allowing the same weighing data to be displayed simultaneously on the crane and the ground. The secondary instrument consists of an instrument signal amplification section, an instrument AD conversion section, a microcomputer processing unit, a 4-20mA current loop output, a 4-20mA AD transmitter output, RS232 communication, RS485 communication, and a power supply section, enabling stable and accurate real-time weight data detection for the metallurgical casting overhead crane. Because the original weighing system only had one load cell per fixed pulley group, and the load cells had built-in signal amplifiers and lacked elastic modulus compensation plates, they were easily burned out when molten iron was added at high temperatures, resulting in unstable data transmission signals. Furthermore, the power supply system for the traveling mill lacked a neutral wire, making it prone to burning out secondary instruments during power outages, severely impacting the stability of the weighing device. The secondary instruments also lacked 4-20mA DC-DC transmitter outputs and RS232 communication circuit modules, preventing data from being sent to the PLC for display and storage. This meant there was no reliable basis for determining the weight of molten iron entering the furnace, thus failing to provide safe production guidance. Specifically:

[0003] 1. The weighing frame of the overhead crane scale for lifting molten metal in metallurgical casting mainly consists of two fixed pulley groups, a support frame, a base, and a weighing sensor. Each fixed pulley group only has a weighing sensor installed on one end, while the other end is not equipped with a weighing sensor and is replaced with a steel block of the same specification. Furthermore, the weighing sensor does not have an elastic modulus compensation plate installed inside, so the accuracy can only reach 2%, with large errors and poor repeatability. That is, after weighing with the same standard ladle, unhooking and placing it on the ground before lifting again, the data shows a deviation from the standard value of at least 300 kg. The signal is easily interfered with, causing the weighing data to fluctuate by 1 to 2 tons during the left, right, forward, and backward movement of the trolley and the crane. Even when the trolley and the crane are relatively stationary, the fluctuation range is still 0.5 tons. It is impossible to provide accurate and stable data on the weight of molten iron entering the furnace for converter smelting. The iron-making worker judges the weight of the molten iron by visually judging the position of the surface of the molten iron in the ladle from the ladle opening. The failure to accurately detect the weight can easily lead to quality accidents. Moreover, the data display takes too long to stabilize, about 30 seconds, which often keeps the converter smelting in a state of waiting for molten iron, affecting the smelting rhythm.

[0004] 2. The signal amplifier is built into the load cell, which not only has poor high-temperature resistance but also cannot adapt to harsh environments such as hoisting steel ladles. If the scrap steel added to the converter is damp or contains debris, the molten iron can easily splash when the overhead crane lifts the ladle to add it to the furnace, causing the load cell and other detection components to burn out and the crane scale to malfunction. The signal transmitted between the scale frame detection group and the secondary instrument is V, which is inconsistent with the mV of other crane scales, and spare parts are not interchangeable.

[0005] 3. Because the overhead crane's electrical power supply system does not have a neutral wire, the 220VAC required by the crane scale is converted from 380VAC to 220VAC by a transformer in the crane's electrical compartment before being supplied to secondary instruments and other detection and control equipment. At the same time, the crane's operation involves switching gears via a linkage, resulting in a large voltage drop. This causes the instruments to frequently flicker or go black. The unstable power supply can lead to the loss of internal parameters in the secondary instruments, which cannot be automatically restored after power is restored and require manual input. In severe cases, it can burn out the secondary instruments, requiring the replacement of the entire instrument. This results in low intelligence, high consumption of spare parts, and seriously affects the stability of the weighing device.

[0006] 4. The secondary instrument is not designed with a 4-20mA DC transmitter output and an RS232 communication circuit module, which makes it impossible to send data to the PLC for display and storage. When there is doubt about the weight of molten iron entering the furnace, there is no basis to follow, and it cannot play a role in guiding production safety.

[0007] 5. When the trolley is stationary, the weighing data changes with the hook height during the lifting and lowering of the load. The weight of the wire rope is accumulated in the sensor section, and the weight of the load cannot be directly displayed. The weight of the wire rope needs to be manually deducted, which introduces errors. Utility Model Content

[0008] The purpose of this invention is to address the shortcomings and defects of existing technologies by providing an information transmission device that improves the detection accuracy of overhead crane scales in metallurgical casting. To improve the detection accuracy of the crane scale, reduce the equipment failure rate, and enhance the safety and reliability of monitoring the operation of the overhead crane transporting liquid metal in metallurgical casting, a weighing sensor is installed on each side of each fixed pulley group, resulting in a total of four weighing sensors installed on the two fixed pulley groups. The signal amplifier is moved from inside the weighing sensor to the signal amplification circuit of the secondary instrument. An elastic modulus compensation plate is also designed inside the weighing sensor. A voltage regulator integrated circuit is added to the power supply of the secondary instrument to ensure continuous power supply during abnormal power outages. The output section is equipped with a 4-20mA DC-DC converter and RS232 communication for PLC display and storage, achieving accurate and stable crane weighing detection, thereby preventing faults such as large signal fluctuations, inaccurate data, and burnout of weighing sensors and secondary instruments.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: an information transmission device for improving the detection accuracy of a metallurgical casting crane scale, comprising two sets of fixed pulley groups 3 and a secondary instrument 7. A connecting shaft 6 is installed within each of the two sets of fixed pulley groups 3, and load cells 4 are installed at both ends of each set of fixed pulley groups 3 near the lower end of the connecting shaft 6. Each of the four load cells 4 contains an elastic modulus compensation plate 8, and all four load cells 4 are electrically connected to the secondary instrument 7. The secondary instrument 7 contains a main control circuit board, which includes a transmitter output unit 71, an RS232 communication unit 74, and a microcomputer processing unit 77. The transmitter output unit 71 and the RS232 communication unit 74 are both connected to the microcomputer processing unit 77.

[0010] Furthermore, it also includes a speed reducer 1 and a wire rope drum assembly 2. The speed reducer 1 is provided in two sets. Each speed reducer 1 is correspondingly provided with a wire rope drum assembly 2 and a fixed pulley assembly 3. The wire rope drum assembly 2 and the fixed pulley assembly 3 are mechanically connected to one side of the speed reducer 1. The wire rope drum assembly 2 is connected to its fixed pulley assembly 3 through a wire rope and is connected to a gantry hook 5.

[0011] Furthermore, the transmitter output unit 71 is a 4-20mA transmitter output unit.

[0012] Furthermore, the secondary instrument 7 also includes a current loop output unit 72, an AD conversion unit 73, an RS485 communication unit 75, and an instrument signal amplification unit 76. The current loop output unit 72 is connected to the RS232 communication unit 74, and one end of the RS485 communication unit 75 is connected to the RS232 communication unit 74, while the other end of the RS485 communication unit 75 is connected to the microcomputer processing unit 77. The microcomputer processing unit 77 is connected to its AD conversion unit 73, and the AD conversion unit 73 is connected to the instrument signal amplification unit 76.

[0013] Furthermore, the instrument signal amplification unit 76 is connected to the weighing sensor 4.

[0014] Furthermore, the weighing sensor 4 includes a sensor body 42, the bottom of the sensor body 42 is recessed inward to form a bottom groove 43, the top of the sensor body 42 is provided with a shaft placement groove 41, and the front end of the sensor body 42 is provided with a wiring terminal 44.

[0015] Furthermore, the fixed pulley group 3 is provided with a sensor support frame 301 for supporting its weighing sensor 4.

[0016] Furthermore, a wire rope compensator is added to the end of the reducer 1.

[0017] After adopting the above technical solution, the beneficial effects of this utility model are as follows: This device has at least the following advantages:

[0018] 1. The system was upgraded from two sensors to four sensors, and an elastic modulus compensation plate was added inside the weighing sensor, which greatly improved the system accuracy. The detection accuracy was improved from less than 2% to better than 0.3%.

[0019] 2. The built-in signal amplification unit of the load cell was removed and replaced with the signal amplification section of the secondary instrument, which improved the high temperature resistance of the load cell. After using a high temperature sensor with a temperature resistance of 250℃, it can adapt to harsh working environments such as high temperature and high dust, molten iron splashing, and lifting steel ladles.

[0020] 3. After the signal amplification unit was moved from being installed inside the weighing sensor to being installed inside the secondary instrument, the signal transmitted between the weighing frame detection group and the secondary instrument changed from V to mV, realizing the standardization of the signal transmission mode and enabling spare parts interchangeability with other overhead crane scales.

[0021] 4. A three-layer voltage regulator integrated circuit is added to the 220VAC power supply input path of the secondary instrument to stabilize the power supply of the secondary instrument, prevent the loss of internal parameters, and ensure long-term safe and stable operation without being affected by voltage drop or power outage.

[0022] 5. A 4-20mA DC transmitter output circuit unit and a serial RS232 communication circuit unit are added to the output terminal of the secondary instrument. The RS232 communication circuit unit is the primary one, and the 4-20mA DC transmitter output circuit unit is the backup interface. When the serial RS232 communication circuit unit fails, the signal transmission will automatically switch to the 4-20mA DC transmitter output circuit unit, so that the signal to the PLC can be transmitted stably and continuously around the clock, providing a fair and impartial basis for the statistics of molten iron consumption in each shift of the converter.

[0023] 6. A wire rope compensator is added to the end of the reducer to ensure that the main trolley remains stationary while the data at different heights during the lifting and lowering of heavy objects remains unchanged, eliminating human estimation errors and improving the detection accuracy of the entire crane scale system. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of this utility model.

[0026] Figure 2 This is a schematic diagram of the structure of the fixed pulley block and the weighing sensor in this utility model.

[0027] Figure 3 This is a schematic diagram of the structure of the weighing sensor in this utility model.

[0028] Figure 4 yes Figure 3 The corresponding top-view structural diagram.

[0029] Figure 5 This is the circuit diagram of the weighing sensor in this utility model.

[0030] Figure 6 This is the circuit diagram of the secondary instrument in this utility model.

[0031] Figure 7 yes Figure 6 An enlarged schematic diagram of the medium-voltage transmitter output unit.

[0032] Figure 8 yes Figure 6 Enlarged schematic diagram of the medium current loop output unit.

[0033] Figure 9 yes Figure 6 An enlarged schematic diagram of the AD conversion unit.

[0034] Figure 10 yes Figure 6 An enlarged schematic diagram of the RS232 communication unit.

[0035] Figure 11 yes Figure 6 An enlarged schematic diagram of the RS485 communication unit.

[0036] Figure 12 yes Figure 6A magnified schematic diagram of the instrument signal amplification unit.

[0037] Figure 13 yes Figure 6 An enlarged schematic diagram of the microcomputer processing unit.

[0038] Figure 14 This is a circuit diagram of the power supply control system for the secondary instrument power input terminal in this utility model.

[0039] Explanation of reference numerals in the attached drawings: 1. Reducer; 2. Wire rope drum assembly; 3. Fixed pulley assembly; 4. Weighing sensor; 5. Gantry hook; 6. Connecting shaft; 7. Secondary instrument; 8. Elastic modulus compensation plate; 9. Sensor support frame; 10. Shaft placement groove; 41. Sensor body; 42. Bottom groove; 43. Wiring terminal; 44. Fixing through hole; 45. Transmitter output unit; 71. Current loop output unit; 72. AD conversion unit; 73. RS232 communication unit; 74. RS485 communication unit; 75. Instrument signal amplification unit; 76. Microcomputer processing unit; 77. Detailed Implementation

[0040] See Figures 1-14 As shown, the technical solution adopted in this specific embodiment is as follows: It includes two sets of fixed pulley groups 3 and a secondary instrument 7. A connecting shaft 6 is installed in each of the two sets of fixed pulley groups 3, and a weighing sensor 4 is installed at both ends of the two sets of fixed pulley groups 3 near the lower end of the connecting shaft 6. An elastic modulus compensation plate 8 is installed in each of the four weighing sensors 4, and the four weighing sensors 4 are electrically connected to the secondary instrument 7. The secondary instrument 7 is equipped with a main control circuit board, which is equipped with a transmitter output unit 71, an RS232 communication unit 74, and a microcomputer processing unit 77. The transmitter output unit 71 and the RS232 communication unit 74 are both connected to the microcomputer processing unit 77. The RS232 communication unit 74 is the primary interface, and the transmitter output unit 71 is the backup interface. When the RS232 communication unit 74 fails, the signal transmission automatically switches to the transmitter output unit 71 to ensure stable storage around the clock and no data loss.

[0041] More specifically, it also includes a speed reducer 1 and a wire rope drum assembly 2. The speed reducer 1 is provided in two sets. Each speed reducer 1 is correspondingly provided with a wire rope drum assembly 2 and a fixed pulley assembly 3. The wire rope drum assembly 2 and the fixed pulley assembly 3 are mechanically connected to one side of the speed reducer 1. The wire rope drum assembly 2 is connected to its fixed pulley assembly 3 through a wire rope and is connected to a gantry hook 5.

[0042] More specifically, the transmitter output unit 71 is a 4-20mA transmitter output unit.

[0043] More specifically, the secondary instrument 7 also includes a current loop output unit 72, an AD conversion unit 73, an RS485 communication unit 75, and an instrument signal amplification unit 76. The current loop output unit 72 is connected to the RS232 communication unit 74, and one end of the RS485 communication unit 75 is connected to the RS232 communication unit 74, while the other end is connected to the microcomputer processing unit 77. The microcomputer processing unit 77 is connected to its AD conversion unit 73, and the AD conversion unit 73 is connected to the instrument signal amplification unit 76. The RS485 communication unit 75 serves as the second communication interface. The electrical signal from the weighing sensor 4 is amplified by the instrument signal amplification unit 76 and then converted by the AD conversion unit 73 before being transmitted to the microcomputer processing unit 77.

[0044] More specifically, the instrument signal amplification unit 76 is connected to the load cell 4. The instrument signal amplification unit 76 amplifies the electrical signal of the load cell 4, thereby ensuring the stability of its data and improving the signal strength and transmission quality.

[0045] More specifically, the weighing sensor 4 includes a sensor body 42, with a bottom recess 43 formed by the inward indentation of the bottom of the sensor body 42, a shaft placement groove 41 on the top of the sensor body 42, and a wiring terminal 44 at the front end of the sensor body 42. The sensor body 42 is connected to its secondary instrument 7 through the wiring terminal 44, while the shaft placement groove 41 is used to place its connecting shaft 6. The sensor body 42 is fixed to the fixed pulley assembly 3 by bolts and fixing through holes 45.

[0046] More specifically, the fixed pulley block 3 is provided with a sensor support frame 301 for supporting its weighing sensor 4.

[0047] More specifically, a wire rope compensator is added to the end of the reducer 1. The wire rope compensator ensures that the weight data during the lifting and lowering of heavy objects is not affected by the weight of the wire rope. The data is displayed the same at different heights of the main hook lifting and lowering, and the weight of the heavy object can be obtained at any time. It eliminates the human error caused by manually subtracting the weight of the wire rope from the total weight, thus improving both detection accuracy and the level of intelligence.

[0048] The working principle of this utility model is as follows: Without changing the overall structure of the crane scale frame, load cells 4 are installed on both sides of each fixed pulley group 3 of the original crane scale, that is, the detection group is changed from two load cells 4 to four load cells 4. At the same time, an elastic modulus compensation plate 8 is added inside the load cell 4. The elastic modulus compensation plate 8 can significantly improve the system accuracy, improving the detection accuracy from less than 2% to better than 0.3%. Furthermore, the built-in signal amplifier of the load cell 4 is removed and replaced with the signal amplification section of the secondary instrument 7, thereby improving the high temperature resistance of the load cell 4. After using a high temperature sensor with a temperature resistance of 250℃, it can adapt to harsh working environments such as high temperature and high dust, molten iron splashing, and lifting steel ladles. After the signal amplifier was moved from the weighing sensor 4 to the secondary instrument 7, the signal transmitted between the detection group and the secondary instrument 7 changed from V to mV, realizing the standardization of the signal transmission mode and enabling spare parts interchangeability with other crane scales. Furthermore, a three-layer voltage regulator integrated circuit was added to the 220VAC power supply input path of the secondary instrument 7 to stabilize the power supply of the secondary instrument, prevent the loss of internal parameters, and ensure long-term safe and stable operation unaffected by voltage drop or power outages. A 4-20mA DC transmitter output unit 71 and an RS232 communication unit 74 are added to the output end of the secondary instrument. Because the 4-20mA DC signal transmission is used, the values ​​displayed by the secondary instrument 7 and the host computer are not completely the same, which sometimes causes disputes in the assessment. However, when the RS232 communication unit is used, the values ​​displayed by the secondary instrument 7 and the host computer are consistent. Therefore, the RS232 communication unit is used as the primary interface, and the 4-20mA DC transmitter output unit 71 is used as the backup interface. When the RS232 communication unit 74 fails, it will automatically switch to the 4-20mA DC transmitter output unit 71 for signal transmission, so that the signal to the PLC can be transmitted stably and continuously around the clock, providing a fair and impartial basis for the statistics of molten iron consumption in each shift of the converter. In addition, a wire rope compensator is added to the end of the main trolley reducer, so that the data display remains unchanged at different heights during the lifting and lowering of the main trolley when the trolley is stationary, eliminating human estimation errors and improving the detection accuracy of the entire crane scale system.

[0049] The above description is only used to illustrate the technical solution of this utility model and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. An information transmission device for improving the detection accuracy of overhead crane scales in metallurgical casting, characterized in that: It includes two sets of fixed pulley group (3), secondary instrument (7), the connecting shaft body (6) is installed in the two sets of fixed pulley group (3), and the two ends of the two sets of fixed pulley group (3) are close to the lower end of the connecting shaft body (6) are installed weighing sensor (4), the four weighing sensors (4) are all installed with elastic modulus compensation sheet (8), and the four weighing sensors (4) are all electrically connected with the secondary instrument (7), the secondary instrument (7) is provided with main control circuit board, the main control circuit board is provided with transmitting output unit (71), RS232 communication unit (74), microcomputer processing unit (77), transmitting output unit (71) and RS232 communication unit (74) are all connected with its microcomputer processing unit (77).

2. The information transmission device for improving the detection precision of the crane scale of a metallurgical casting crane according to claim 1, characterized in that: It also includes a speed reducer (1), a steel wire rope drum group (2), the speed reducer (1) is provided with two groups, a group of speed reducer (1) is correspondingly provided with a group of steel wire rope drum group (2) and a group of fixed pulley group (3), and the steel wire rope drum group (2) and the fixed pulley group (3) are all mechanically connected to one side of the speed reducer (1), the steel wire rope drum group (2) is connected with the fixed pulley group (3) through the steel wire rope and is connected with the gantry hook (5).

3. The information transmission device for improving the detection precision of the crane scale of a metallurgical casting crane according to claim 1, characterized in that: The transmitting output unit (71) is a 4-20mA transmitting output unit.

4. The information transmission device for improving the detection precision of the crane scale of a metallurgical casting crane according to claim 1, characterized in that: The secondary instrument (7) also includes current loop output unit (72), AD conversion unit (73), RS485 communication unit (75) and instrument signal amplification unit (76), the current loop output unit (72) is connected with the RS232 communication unit (74), and one end of the RS485 communication unit (75) is connected with the RS232 communication unit (74), the other end of the RS485 communication unit (75) is connected with the microcomputer processing unit (77), the microcomputer processing unit (77) is connected with the AD conversion unit (73), and the AD conversion unit (73) is connected with the instrument signal amplification unit (76).

5. The information transmission device for improving the detection precision of the crane scale of a metallurgical casting crane according to claim 4, characterized in that: The instrument signal amplification unit (76) is connected with the weighing sensor (4).

6. The information transmission device for improving the detection precision of the crane scale of a metallurgical casting crane according to claim 1, characterized in that: The weighing sensor (4) includes a sensor main body (42), a bottom recess (43) is formed in the bottom of the sensor main body (42), an axle body placing groove (41) is arranged on the top of the sensor main body (42), and a wiring terminal (44) is arranged on the front end of the sensor main body (42).

7. The information transmission device for improving the detection precision of the crane scale of a metallurgical casting crane according to claim 1, characterized in that: The fixed pulley group (3) is provided with a sensor support frame (301) for supporting the weighing sensor (4).

8. The information transmission device for improving the detection precision of the crane scale of a metallurgical casting crane according to claim 2, characterized in that: The end of the speed reducer (1) is additionally provided with a steel wire rope compensator.

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