LIQUID FEEDING DEVICE, METHOD FOR PREDICTING OUTPUT AMOUNT OF LIQUID FEEDING DEVICE, AND METHOD FOR CONTROLLING LIQUID FEEDING DEVICE

PROBLEM TO BE SOLVED: To predict an output amount that is accurately outputted from an output port even if a state of a liquid body changes.SOLUTION: A liquid feeding device includes: a liquid feeding step of feeding a liquefied material stored in a storage part to a liquid feeding pipe by motor driving; an output step of outputting the liquefied material supplied from the liquid feeding pipe from the output part through the output pipe; a circulation step of collecting the liquefied material supplied from the liquid feeding pipe to the storage part through the circulation pipe; a switch step of switching a flow path of the liquefied material from the liquid feeding pipe into either the output pipe or the circulation pipe; a measuring step of measuring the liquid feeding amount of the liquefied material in the liquid feeding pipe; a torque change amount calculation step of calculating a change amount of a liquid feeding torque value before and after flow path switching timing in a liquid feeding part; and a prediction step of predicting the output amount of the liquefied material from the output part by using an average value of the change amount of the liquid feeding torque value before and after the flow path switch timing and the liquid feeding amount of the liquefied material in the liquid feeding pipe in the measuring step.