Pressurizing pump device, liquid ejection apparatus and method of controlling pressurizing pump

摘要

In a printing apparatus of an off-carriage type, when a pump motor (28) is rotated regularly for delivering pressurizing air to an ink cartridge, rotation thereof is converted into a linear reciprocating movement of a pressing member (39) by a cam mechanism (33) and a pressurizing operation is executed by repeating to operate to expand and contract a diaphragm (37). On the other hand, the pump motor is started to rotate inversely, a driven part (52) is rotated by a friction clutch mechanism (48), and a pressing portion (52b) of the driven part is brought into contact with a valve opening lever (55) of an atmospheric release valve (22). At this occasion, the valve opening lever is pivoted to bring a valve hole (56) into an opened state and pressurizing air is discharged to outside by bringing the atmospheric release valve into an opened state.