| 摘要 |
PURPOSE:To surely detect the amount of resin supplied to a hopper and the amount of resin in the hopper without being effected by a band of resin wastes, by a method wherein the hopper for an extruder is supported by a gravimeter so as to measure the weight of the hopper in order to detect the amount of resin supplied to the hopper and the amount of resin in the hopper. CONSTITUTION:When a measured signal which corresponds to the decreased amount of resin in a hopper 14 due to the lead-in of the resin to an extruder 20 is outputted from a gravimeter 17, a microcomputer 21 operates the measured signal so as to compare the result of the operation with the lower limit data, which is inputted in advance and corresponds to the lower limit amount of resin. Further, when the lower limit data coincides with the result of the operation, the microcomputer 21 controls solenoid valves 25a and 12 so as to hole the valves open and at the same time puts an air compressor 26 into actuation. Accordingly, resin is fed to the hopper 14 again and, in addition, the measured signal corresponding to the amount of the resin fed to the hopper 14 is also outputted from the gravimeter 17. At the time, when the result of the operation based on the measured signal coincides with an upper limit data, the microcomputer 21 gets back the solenoid valves 25a and 12 to their closed states and at the same time stops the air compressor 26. |
