| 摘要 |
PURPOSE:To save power, in a hydraulic circuit of the injection molding machine, by a method wherein a combination of a plurality of hydraulic pumps necessary and satisfactory to supply an amount of oil determined according to a preset value for a hydraulic cylinder and the like can be obtained automatically. CONSTITUTION:At the same time that the opening of a proportional electromagnetic valve 8 is determined by a set point from a presetter 10 and an amount of oil to supply for a cylinder 11 is selected, a preset positional signal of the presetter 10 is sent to a direction-change-over valve selecting circuit 18. Signals are given automatically in the direction-change-over-valve electing circuit 18 so that the combination of a plurality of hydraulic pumps 1, 2, 3 necessary and satisfactory to supply the cylinder 11 with an amount of oil selected by this set point is realized by magnetizing or demagnetizing a plurality of direction change-over valves 15, 16, 17. The plurality of hydraulic pumps 1, 2, 3 specified by the said signals are loaded or unloaded independently to control the amount of oil. |
