Needle cartridge for drug injection and drug injection device including the same

A needle cartridge for drug injection and a drug injecting device including the same, comprising:

• the needle cartridge comprising a needle;
• a handpiece body including a syringe formed on an upper portion, and a cartridge coupling unit and a needle coupling unit formed on a front;
• a syringe pressing unit including a power source mounted inside the handpiece body, a shaft connected to the power source and rotated, and a pusher which is coupled to the shaft, is inserted into a moving groove formed in a longitudinal direction in the upper portion of the handpiece body, and is moved to push a plunger of the syringe;
• a needle driving unit mounted inside the handpiece body and reciprocating the needle of the needle cartridge in forward and backward directions;
• and
• a position control unit that moves a position of the needle driving unit in the handpiece body to adjust a length of the needle pulled out of the needle cartridge,
• wherein the needle cartridge comprises:
• a cartridge body to be in contact with skin;
• a fitting tube body coupled to a rear end of the cartridge body, and including an injection port formed on an outer peripheral surface, an opening, formed on one side, for fitting with a connection end, a mounting end formed on the outer peripheral surface on other side, and a protrusion formed on the mounting end;
• a needle assembly including a rod to be inserted into the fitting tube body and coupled with the needle driving unit;
• and
• the connection end formed at other end and coupled with the fitting tube body, the needle coupling unit comprises:
• a bar having a predetermined length;
• a ring part formed at one end of the bar and having a coupling hole coupled with a bearing;
• and
• a fastening tube body formed at the other end of the bar and having a protrusion coupling hole into which the rod of the needle cartridge is coupled, the needle assembly includes
• the rod to be inserted into the fitting tube body and coupled with the needle driving unit,
• the cartridge coupling unit is open on both ends, and includes a passage formed therein, and an insertion groove formed on an outer peripheral surface, and
• the protrusion of the mounting end and the insertion groove of the cartridge coupling unit are fitted with each other.