An upside-down pump, which comprises a bottle body (1), a cap and a pump core assembly, the said pump core assembly is disposed on the bottom mouth of the bottle body through a large ring (17), the cap is disposed at the liquid outflow hole of the pump core assembly, the pump core assembly comprises a pump body, a valve needle (9), a spring (10) and a piston (13);
- wherein the pump body of the said pump core assembly comprises an outer pump body (2) and an inner pump body (14), the coupling joint of the outer pump body and the inner pump body is provided with a sealing ring (18) and tightened and securely held to the bottle mouth of the bottle body (1) through the large ring (17), the inner pump body is securely fastened in the outer pump body, the valve stem cavity (1302) at one end of the piston (13) extends out of the large ring, the outer diameter of the piston ring at the other end of the piston is sealed against the inner diameter of the inner pump body, the bottom of the center hole of the piston fits with one end of the connecting rod (12), the inner wall of the center hole of the piston at the coupling joint is provided with a diversion groove (1301), the outer diameter of the other end of the connecting rod fits with the liquid inflow cavity of the inner pump body, a valve needle (9) is disposed in the connecting rod, the needle head at one end of the valve needle is securely fastened to one end of the valve sleeve (8), the outer diameter of the valve needle and the valve sleeve in the connecting rod is provided with a spring (10), one end of the spring abuts against the other end of the valve needle in the connecting rod, a floating clearance is disposed between the valve needle in the connecting rod and the center hole of the piston, the other end of the spring abuts against the outer diameter ring rib at the other end of the valve sleeve, a side thru-hole (801) is disposed in the outer diameter ring of the valve sleeve, a second ball (6) is disposed on the inner diameter bottom hole of the inner pump body at the bottom coupling joint of the valve sleeve, the bottom hole of the inner pump body extends from the suction pipe hole on one side of the bottom of the outer pump body and fits with the first thru-hole on one side of the connecting sleeve (4), an annular clearance is disposed between the outer diameter of the inner pump body at the coupling joint and the inner diameter of the connecting sleeve, the second thru-hole on the other side of the connecting sleeve fits with one end of the upside-down suction pipe (11), a first ball (5) is disposed at the coupling joint, the other end of the upside-down suction pipe extends to the top inner wall in the bottle body, the bottom joint of the connecting sleeve fits with one side of the base sleeve (3), a knurled column (301) is disposed at the other end of the base sleeve, the said knurled column of the base sleeve is inserted in the auxiliary hole on the auxiliary hole base sleeve on the other side of the bottom of the outer pump body, protruded to the bottom and a gap (201) is disposed in the hole of the protrusion, and the first thru-hole and the second thru-hole in the bottom cavity at the joint of the connecting sleeve and the base sleeve communicate with each other.