Bellows pump device

A bellows pump device comprising:

• a first bellows and a second bellows expandable/contractible between a most expanded state and a most contracted state independently of each other and configured to suck a transport fluid thereinto by expansion thereof and discharge the transport fluid therefrom by contraction thereof;
• a first driving unit configured to drive the first bellows to actively expand and contract;
• a second driving unit configured to drive the second bellows to actively expand and contract;
• a first detection unit configured to detect an expanded/contracted state of the first bellows;
• a second detection unit configured to detect an expanded/contracted state of the second bellows;
• and
• a control unit configured to perform operation control of the first driving unit and the second driving unit on the basis of respective detection signals of the first detection unit and the second detection unit such that, after expansion drive of the first bellows is stopped in a first mid-expansion state before the most expanded state, contraction drive of the first bellows is started before the second bellows reaches the most contracted state, and after expansion drive of the second bellows is stopped in a second mid-expansion state before the most expanded state, contraction drive of the second bellows is started before the first bellows reaches the most contracted state.