Drug injection device

A drug injection device comprising:

• a case having a drug container located on one side therein;
• a discharge amount adjustment module provided on a side of the case different from the side of the case the drug container is located on, and being rotated by a set angle only in one direction;
• a rotation amount detection module configured to detect a rotation value of a deceleration unit and to transmit detected data to a controller;
• and
• a locking module configured to lock the deceleration unit in order to limit rotation of the deceleration unit when the rotation value detected by the rotation amount detection module reaches a set value,
• wherein the discharge amount adjustment module comprises:
• a dial spring having a first fastening hole formed in a center thereof such that a fixed shaft is coupled to the first fastening hole, spring arms formed radially on an outer circumferential surface of the dial spring, and a catching protrusion formed at an end of each spring arm;
• a dial configured to be rotated in a state in which a part of the dial is exposed through an opening of the case, wherein the part of the dial exposed through the opening of the case is configured to be directly manually rotated by a user, wherein when the dial is directly manually rotated by the user the drug in the drug container is discharged;
• the dial being provided with a coupling recess coupling the dial spring to the dial while having a second fastening hole of the dial and unidirectional teeth radially formed on an inner circumferential surface of the coupling recess;
• and
• the deceleration unit comprising a combination of gears and coupled to the dial so as to be interlocked therewith, the deceleration unit being configured to discharge some amount of the drug stored in the drug container while performing deceleration by multistage connection upon rotation of the dial,
• wherein the rotation amount detection module comprises:
• a magnetic body inserted into an end of a power gear of the deceleration unit so as to be rotated upon operation of the discharge amount adjustment module;
• and
• a sensor configured to detect a rotation value of the magnetic body and to transmit detected data to the controller,
• wherein the locking module comprises:
• an upper bracket provided in a bent state;
• a lower bracket having one end extending through a lower part of a vertical portion of the upper bracket and a gear stopper with gear teeth configured to stop rotation of a lock gear of the deceleration unit provided at an end of the lower bracket different from the lower bracket's end which extends through the upper bracket, the lock gear having an auxiliary gear formed at an end thereof;
• a magnet provided at a lower part of the lower bracket;
• and
• an electromagnet fixed to a lower part of a horizontal portion of the upper bracket, the electromagnet being magnetized by a flow of current, the electromagnet being configured to couple or separate the gear stopper to or from the lock gear of the deceleration unit according to polarity conversion;
• and
• a compression spring configured such that one end of the compression spring is supported by an end of the horizontal portion of the upper bracket vertically above the electromagnet and another end of the compression spring is supported by the end of the lower bracket extending through the vertical portion of the upper bracket,
• wherein the electromagnet and magnet are both disposed between the compression spring and the auxiliary gear in a direction parallel with the auxiliary gear's axis of rotation,
• wherein the controller sets a rotation value of the dial of the discharge amount adjustment module, and performs control of the gear stopper such that manual rotation of the dial is stopped when the dial is rotated by the rotation value which was set in the controller,
• wherein the unidirectional teeth are formed with alternating inclined and vertical surfaces such that, when the inclined surface contacts the catching protrusion of the dial spring, the spring arms are compressed to rotate the dial, and when the vertical surface contacts the catching protrusion of the dial spring, the spring arms are not compressed,
• wherein the drug in the drug container is discharged while the catching protrusion of the dial spring contacts the inclined surface from one end of the inclined surface to the other end of the inclined surface,
• wherein when the gear teeth of the gear stopper is engaged with the gear teeth of the auxiliary gear the dial cannot be rotated by the user and when the gear teeth of the gear stopper is disengaged from the gear teeth of the auxiliary gear the dial can be rotated by the user, and
• wherein the gear stopper is engaged with the auxiliary gear by moving vertically upward and the gear stopper is disengaged from the auxiliary gear by moving vertically downward.