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Development and application of hydraulic static scale on profiled billet roller table

Abstract: in order to ensure the accuracy of profiled billet measurement in the new area, a profiled billet roller table scale is designed, manufactured and installed. This paper introduces the design, development, manufacturing and installation process of the roller scale and its automatic control characteristics. The scale has the characteristics of simple installation, high weighing accuracy, convenient maintenance and stable operation. Its development and application have achieved good results and achieved the expected purpose

key words: hydraulic static scale weighing control system data remote transmission


according to the production requirements of Laiwu Iron and steel medium-sized plant in the new area, it is necessary to install a roller scale for inter plant settlement and measurement on the roller table from continuous casting to large-scale profiled billet transportation. In order to ensure the accuracy of the measurement of the profiled billet in the new area, the time for measuring the hot rolled profiled billet should be shortened as far as possible to meet the requirements of the fast pace of production on the measuring time of the weighing instrument. Therefore, the weighing instrument is designed as a static measuring method; The traditional installation of single weighing platform requires the hydraulic device to rise and fall at the same time to meet the demand. There are many interference factors and large measurement errors, which are incompatible with production. Therefore, a 40 ton shaped blank roller scale is designed, manufactured and installed between the roller tables to meet the accurate measurement requirements of 30 tons of gross weight. Since the roller deck has been installed, there is no reserved position for installing the scale, and it has been put into production, so it is difficult to install the roller deck scale

in view of the above reasons, we decided to install four hydraulic weighing devices between the roller tables, assemble the hydraulic cylinder and the four heat insulation tables into four weighing tables respectively, and start the four weighing tables to a certain position through the hydraulic system for measurement, which will not affect the production (install them at the time of maintenance), protect the original roller table from being affected, and save construction funds

1 engineering design

1.1 mechanical design

the table top length is determined as 9.6 m according to the length of profiled blanks, so as to ensure that various profiled blanks will never be weighed continuously. According to the weighing range and business volume, after repeated consideration and field survey, each group of roller table motor base is used as the foundation, 20mm thick steel plate is welded with the roller table foundation plate, and four steel plates are used as the foundation of the scale. After each steel plate is leveled, drill and tap, fix 8 sensors on 4 steel plates, and weld 4 limiters on each steel plate to limit the movement of the scale hydraulic device. Every 2 sensors are fixed with the scale hydraulic device by bolts to form a scale force bearing device, and 8 sensors form 4 scale force bearing devices. The scale body composed of four independent hydraulic devices is operated by the hydraulic workstation to jointly bear the weight of steel billets. At the same time, the hydraulic device is used to adjust the balance, so as to reduce the influence of table deformation caused by the rise and fall of the scale platform and ensure the stable and reliable operation of the scale body

the design of the sensor device fully takes into account the factors such as the sensor can not be offset, the harsh use environment, the protection of the signal line and the accurate transmission of the signal. The method of placing the sensor under the hydraulic device is adopted. Two sensors support a weighing device. The weighing device consists of the hydraulic device and the thermal insulation steel plate platform. The dynamic stiffness testing machine mainly uses the opening of the test software to carry out the experiment The rubber elastomer and shock absorber are composed of the test of message stiffness, damping coefficient, damping angle and other parameters and the fatigue resistance test, which realizes the protection of the sensor and related signal lines. In particular, the hydraulic structure can adjust the height and level of the scale body, and it can be automatically adjusted by the hydraulic system after being raised by the pressure of the billet, so that all the force bearing devices of the scale body are stressed, and then they can be raised together to form a unified whole with the profiled billet, and the profiled billet can be measured after being separated from the roller table

the limiter of this scale adopts the hydraulic limit method. The limit is under the hydraulic structure, so it is convenient and reliable to adjust the limit. It is convenient for lubrication and maintenance while limiting, making the scale platform more stable

1.2 selection of electrical appliances

eight 5T load cells are used in the electrical part. The load cell is equipped with a limit device to effectively prevent the sensor position from shifting, ensure the vertical force on the sensor, reduce the inclination caused by uneven force on the sensor, and avoid the fault of weighing signal error caused by the displacement of the scale

the electrical part is also equipped with an 8-wire junction box to connect pt650 weighing display. The instrument has strong load capacity, and a/d conversion adopts Δ-Σ Method, fast conversion speed, high sampling speed, up to 20 times/s, with standard RS232 output interface. The instrument has accurate display and stable operation, and can be used with multiple weighing instruments. The system is applicable to the site requirements and is installed as soon as it is used

the weighing and measuring software is easy to operate and has strong human-computer interaction. It can quickly and accurately replace the original measuring program and make the measuring data more authentic and accurate

in order to improve the automation and intelligence of measurement, the hydraulic scale realizes unattended measurement and weighing, and realizes remote monitoring and data transmission. The weighing signal is connected to the RS232 input interface of nport5210 network data module through the standard RS232 output interface of pt650 weighing display instrument, and then the output signal of the module is connected to the network switch or data optical transceiver and transmitted to the terminal computer through optical cable line for comprehensive processing of various data. At the same time, the network video technology is used to realize the remote monitoring of the weighing instrument equipment, and the operation of the weighing instrument is monitored through the camera located above the operating room. The image signal can be transmitted remotely through a pair of video optical terminals and optical cables. The real-time monitoring of remote images and the adjustment of various actions can be realized on the hard disk video recorder of the terminal

2 scale body processing and manufacturing

2.1 scale body table and related parts processing

because the 4-section scale platform is assembled into a whole with profiled blanks, it is easy to measure various profiled blanks. The scale surface is paved and fully welded with heat-insulating steel plate. In order to prevent deformation and meet the needs of support strength, the heat-insulating steel plate is installed at the main bearing beam to form a load-bearing scale body with hydraulic installation as the main dry frame. The processing and welding of parts shall comply with national standards. The scale limit is adjusted by small bolts

2.2 table top processing

due to the long weighing table top, there may be inclined deformation after the four weighing tables are connected as a whole. Therefore, the overall stability of the scale body should be increased as much as possible during the hydraulic process. In case of minor deformation, the hydraulic device can be used to make fluid replenishment adjustment separately to reduce the impact caused by deformation, impact, vibration and other factors. The overall structure is shown in Figure 1

3 the software selects

bd control system to receive the signal from continuous casting and transport the billet from continuous casting to the weighing roller table of heating furnace. After the steel head reaches the predetermined position of weighing roller table (monitored by high-temperature photoelectric switch), BD control system hands over the control right of roller table to the weighing control system

after the weighing control system receives the roller table control permission signal from the BD control system, the four groups of weighing roller tables will rise at the same time, and send a measurement permission signal to the metering system when they are in place (or manually operate the lifting and send the roller table operation completion signal through the button. At this time, it is not necessarily shared by the four groups). After a few seconds of delay, the weighing roller table will fall. After lowering in place, the weighing roller table release signal will be sent to the BD control system, and the BD control system will carry out residual control after receiving this signal

in addition to allowing the metering signal, the BD control system also needs to send a hot billet and cold billet signal to the metering system, and transmit the billet length signal from the heating furnace to the metering system

the software design is based on the principles of friendly interface, simple operation and strong human-computer interaction. The program is divided into five basic modules: weighing, data management, report printing, scale calibration and data modification. Among them:

① the weighing module mainly completes the functions of data collection and processing and weighing data storage of the slab scale

② the data management module mainly completes the query of symmetric heavy data, supports multiple query methods, and displays the query results in tabular form

③ the print module mainly realizes the functions of printing shift reports and detailed reports of measurement documents

④ the scale calibration module monitors the data of the blank scale during scale calibration

⑤ the main function of the data modification module is that the operator can revise the out of limit data of the profiled billet scale when rechecking it

4 remote monitoring and data transmission

the monitoring video recorder can realize real-time video recording of the measurement process, and realize on-site remote monitoring and control of the front-end pan tilt and lens. After conversion, the data signal is transmitted through optical fiber to complete the remote data transmission from the data end to the control end of the system. In the measurement center, as shown in Figure 1, an industrial computer is set in the duty room to undertake the daily measurement work such as the reception, storage, management, statistics and document issuance of weighing data

the front-end equipment takes the hard disk video recorder as the core, connects the keyboard, mouse, display, video cable, etc., and completes the functions of monitoring, video recording, control, etc. The picture taken by the front end is clearly displayed on the display through the transmission part and the hard disk video recorder, and the picture is free of bad spots and scrolling. The remote control signal adopts the international standard communication mode, from the hard disk video recorder to the decoder, and then the decoder analyzes the signal to control the front-end equipment pan tilt, lens, wiper electrical film, fan, heater, etc., although the number is small compared with the packaging film

5 conclusion

4 table hydraulic roller table combined scale has been applied in Laiwu Iron and Steel Co., Ltd. for the first time and achieved good results. The scale has the characteristics of simple installation, high weighing accuracy, convenient maintenance and stable operation. It plays an important role in the continuous measurement of profiled billets in Laigang new area. Compared with the previous weighing methods, it improves the adaptability of the weighing instrument, reduces the waste of human resources, reduces the measurement error, makes the weighing data more timely and accurate, and ensures the safety and smoothness of the production line. The computer prints the documents, reduces the probability of error, and improves the measurement accuracy

4 weighing platform combination is a perfect innovation, which has realized the remote unattended metering mode and the metering automation and intelligence of hydraulic roller scale, and has been praised by users. (end)

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