A spiral guide mechanism for syringe comprises a two-way spiral guide tube group, a screwing ring, one-way ratchet, a spiral pusher and an injection pusher group. The two-way spiral guide tube group contains an external spiral duct and an internal spiral duct screwed within the external spiral duct the screwing ring is assembled in the external spiral duct the one-way ratchet is assembled in the one-way ratchet groove of the internal spiral duct the spiral pusher is fitted in the two-way spiral guide tube group and screwed in the screwing ring the injection pusher of the injection pusher group is penetratingly disposed in the one-way ratchet and can be penetratingly disposed in the spiral pusher for slidably moving in the axial direction when being applied to the syringe, the spiral guide mechanism can utilize a large pitch stroke assembly structure of the two-way spiral guide tube group, in conjunction with a small pitch stroke assembly structure between the screw joint and the spiral pusher, thus transforming the straight pressing force of the injection pusher group into a rotational force, and converting to an injection thrust of small stroke rotation via the large stroke rotary thrust, so as to achieve the purpose of quantitative medicament injection in an effortless and simple manner.一種注射器的螺旋導引機構,其包含有雙向螺旋導引管組、螺接環、單向棘輪、螺旋推桿與注射推桿組,雙向螺旋導引管組包含外螺旋導管與螺接於外螺旋導管內之內螺旋導管,螺接環組設於外螺旋導管內,單向棘輪組設於內螺旋導管的單向棘齒槽中,螺旋推桿裝設於雙向螺旋導引管組內且螺接螺接環中,注射推桿組以其注射推桿穿設於單向棘輪中且能軸向滑移地穿設於螺旋推桿,當其應用於注射器中,該螺旋導引機構能利用雙向螺旋導引管組之大螺距行程組合構造,搭配螺接頭與螺旋推桿間之小螺距行程組合構造,使按壓注推桿組之直向按壓力量轉換為旋轉力量,經由大行程旋轉推力轉換至小行程旋轉之注射推力,以省力的簡便操作方式達到定量注射藥劑之目的。50‧‧‧雙向螺旋導引管組51‧‧‧外螺旋導管511‧‧‧螺管部512‧‧‧環端壁513‧‧‧管端514‧‧‧螺旋導槽515‧‧‧棘齒彈片516‧‧‧定位凹部52‧‧‧內螺旋導管521‧‧‧螺旋導塊522‧‧‧逆止環紋523‧‧‧軸向導槽524‧‧‧單向棘齒槽525‧‧‧樞接部60‧‧‧螺接環61‧‧‧螺孔62‧‧‧定位凸部70‧‧‧單向棘輪71‧‧‧輪體72‧‧‧單斜向棘齒彈片73‧‧‧中孔80‧‧‧螺旋推桿81‧‧‧劑量控制段82‧‧‧限位凸緣83‧‧‧軸孔84‧‧‧活塞頂塊85‧‧‧定位邊90‧‧‧注射推桿組91‧‧‧注射推桿911‧‧‧桿體912‧‧‧按壓端部913‧‧‧定位擋塊92‧‧‧推桿端蓋
