Continuous liquid infusion device

A continuous liquid infusion device comprising:

• a liquid syringe section;
• and
• a driving pump section to be mounted on said liquid syringe section, wherein:
• said liquid syringe section has a liquid infusion port at one end and an opening at the other end connected with a bottom end part of said driving pump section;
• a liquid filling chamber in communication with the liquid infusion port;
• and a pushing member including a peripheral edge in sliding contact with an inner circumferential wall of the liquid filling chamber, the pushing member being slidable due to the peripheral edge to reciprocate liquid-tightly and air-tightly in an axis direction of said liquid syringe section;
• said driving pump section has a liquid pushout plunger barrel and an internal negative pressure cylinder to be inserted and fitted into the liquid pushout plunger barrel, the liquid pushout plunger barrel including the bottom end part abutting on an upper edge of the pushing member and at least two pressing arms in connection with the bottom end part and to be inserted and fitted into the liquid filling chamber along the inner circumferential wall, and the internal negative pressure cylinder containing a negative pressure chamber and having a piston inserted and fitted thereinto, the piston sliding in the axis direction of the negative pressure chamber air-tightly to produce negative pressure;
• and
• by sliding the pressing arms of said driving pump section toward an upper end, the piston in the negative pressure chamber is slidingly pushed up in the axis direction to produce negative pressure in the negative pressure chamber, and the liquid pushout plunger barrel is biased toward the upper edge of the pushing member via a locking member engaged with the piston by utilizing returning force of the piston due to the negative pressure so that the biased pushing member pushes liquid in the liquid syringe out of the liquid infusion port.