PURPOSE: To secure a liquid-conveying device consisting in a simple construction capable of conveying a liquid continously from a discharge port with non-joint motion owing to operations of each pair of discharge valves and suction valves, attendant upon the discharge and suction of two plunger pumps to be connected with each other in parallel.

CONSTITUTION: A threaded cylinder 2a is attached to a main shaft tip of a motor 2, and with turning operation of an adjusting lever 3, a screw thread 5 of a cam rod 4 capable of adjusting an axial position is screwed in the threaded cylinder 2a. This cam rod 4 forms a cam groove 6 to be varied in depth along the driven direction toward the outer surface, and with rotation of this cam rod 4, slide levers 10a and 11a of a pair of plunger pumps 10 and 11 installed in a machine body 12 is made so as to be reciprocated. In addition, inside the machine body 12, there are provided with each pair of liquid-conveying holes 13 and return liquid holes 14 so as to be interconnected to each of these pumps 10 and 11, while each of these holes 13 and 14 are interconnected to a discharge valve 15 and a suction valve 16. And, the liquid-conveying hole 13 is interconnected to a discharge port 21 from the discharge valve 15, while the return liquid hole 14 to a suction port 22 from the suction valve 16, respectively.