The weighing and force measuring instrument controls the loading pressure and unloading pressure through a portable electric hydraulic station. A manual pressure reducing valve is installed at the pump outlet to manually adjust the pressure at the pump outlet. It is connected to a manual flow divider throttle valve through a hose. The manual flow divider throttle valve is respectively connected to three check valves through three hoses, and each check valve is successively connected to one hydraulic jack. And install a weighing and force gauge at the oil inlet of each hydraulic jack to display the oil pressure of the hydraulic jack. The hydraulic system is equipped with flow valves and check valves to ensure the stable loading of the hydraulic jack and the stable pressure-holding time after loading.
020-34563445Calibration platforms A, B and C are respectively arranged directly above or below the Weighing modules of the three hopper scales. On each inspection platform, one digital weighing calibrator and one hydraulic jack are configured. The oil pump is directly driven by the motor to apply pressure to the hydraulic jacks on calibration platforms A, B and C in parallel and synchronously. The movement of the piston of the hydraulic jack causes the corresponding standard weighing calibrator and the weighing module to be calibrated to be loaded simultaneously, resulting in the oil pressure weighing and digital weighing modules of each hydraulic jack respectively outputting signals.
The oil pressure signals P1, P2 and P3 input by the corresponding hydraulic jacks on calibration bench A, Calibration bench B and Calibration bench C, as well as the force signals F1, F2 and F3 output by the corresponding weighing calibrator, are all transmitted to the signal acquisition box for summary processing and then sent to the control system. The control system receives the oil pressure values of three hydraulic jacks and the force values and total values of three weighing calibrators respectively, and combines them with the total value output by the weighing module of the hopper scale to be calibrated to complete the calibration of the hopper scale. The working status of the calibrated weighing module can be diagnosed by gradually loading the hydraulic jack multiple times and analyzing the output results collected multiple times.
In accordance with the principle of convenience in use and maintenance, the calibration device should be capable of being installed and calibrated at any time based on the actual situation and needs on site. During the process, there is no need to disassemble the hopper scale. After calibration, the portable calibration device can be disassembled. The operation should be simple and efficient, and it should be convenient for maintenance and upkeep. Moreover, the same calibration device can be used for the calibration of other hopper scales. Each set of the calibration bench consists of one gantry frame (fixed and welded to the foundation at the bottom of the frame), one digital weighing module, one hydraulic jack, a weighing force gauge and other accessory connecting parts.
