Piston pump for the dosed transport of liquid and pasty media, in particular for the micro metering and injection molding machine with a piston pump

摘要

Piston pump (10) for the metered feeding of a liquid, comprising- a liquid chamber (11), which via a suction channel (14) with the liquid and can be filled with a dispensing channel (15) for outputting of the liquid fluid can be connected;- a in the fluid chamber (11) arranged intake piston (17); and- a in the fluid chamber (11) arranged ejecting pistons (18); wherein the piston pump (10) has the following features:- the suction piston (17) is arranged between a first position, a second position, and a third position within the fluid chamber (11), where the suction piston (17)- in its first position the intake conduit (14) closes,- in its second position the intake conduit (14) and- in the third position, releases the dispensing channel (15);- the discharging piston (18) is arranged between a first position and a second position within the fluid chamber (11), where the discharging piston (18)- in its first position the intake conduit (14) and- in its second position the intake conduit (14) closes;- by displacing the aspiration plunger (17) of its second position in the direction of the third position in the case of, in the first position, the discharging piston (18) in the liquid is sucked out of the fluid chamber (11); andn="19"- by displacement of the discharging piston (18) in the direction of its second position in the third position in the intake piston, the liquid through the dispensing channel (15), wherein the piston pump (10) is characterized by the following features:- the fluid chamber (11) is connected via a ventilation channel (16) can be connected with the atmosphere fluid;- the suction channel (14) is between the dispensing channel (15) and the vent duct (16); and- in a third position of the discharging piston (18), both the intake conduit (14) as well as the ventilation channel (16), so that the fluid chamber (11) that is fluidly connected with the atmosphere.