A drug injection device, comprising:
- a first sub-line of which a first end joins with a main line, connected from a first drug storage part for storing a first drug to be injected into a body of a patient such that the first drug flows therein;
- a second drug injection part which is connected to a second end of the first sub-line and is configured to apply pressure to inject a second drug that is different from the first drug;
- and
- a second drug pumping part which is connected to the first sub-line, and is configured to apply pressure to push the second drug which has been injected into the first sub-line by the second drug injection part toward the main line,
- wherein the second drug pumping part comprises:
- a pumping solution injector for injecting a pumping solution to push the second drug into the main line;
- a third sub-line for connecting the pumping solution injector to the first sub-line;
- a pumping solution suction line branched from the third sub-line at a location between the pumping solution injector and a junction where the third sub-line joins with the first sub-line, the pumping solution suction line defining a flow path for supplying a pumping solution to be sucked into the pumping solution injector;
- and
- a sliding lock valve located on the third sub-line between the junction where the third sub-line joins with the first sub-line and a point where the pumping solution suction line is coupled, wherein the sliding lock valve comprises:
- a valve body including a communication hole which is open at both ends to be connected to a tube of the third sub-line and defines a fluid passage through the valve body, and a sliding slit formed in a direction intersecting the communication hole;
- and
- a shutter disposed within the sliding slit and configured to block a fluid flow or regulate a flow rate through the communication hole according to a sliding movement of the shutter,
- wherein a protrusion having elasticity is formed at a predetermined interval in one of the sliding slit or the shutter in contact with the sliding slit, and a groove is formed at an interval corresponding to the predetermined interval of the protrusion in the other one of the sliding slit or the shutter in contact with the sliding slit such that the protrusion and the groove are snapped by elasticity.