A safety syringe device is disclosed, which comprises a syringe, a needle head device, an actuation main body part, and a protection cover. The actuation main body part comprises a fixed U-shaped part, a mobile U-shaped part, a membrane soft hinge part and a port. The fixed U-shaped part and the mobile U-shaped part are connected via the membrane soft hinge part therebetween. A V-shaped elastic body connected on two ends of the port of the actuation main body part is utilized to provide the fixed U-shaped part and the mobile U-shaped part with a sufficient elastic action force while the fixed U-shaped part and the mobile U-shaped part are relatively turned and flipped. Besides, a distal end of the mobile U-shaped part is provided with a to-be-inserted part that is connected with a plugged part formed on a front end of the protection cover. The protection cover is turned toward the needle head before the disposal of the used syringe, so that the mobile U-shaped part and the protection cover are forced to bendingly rotate toward the fixed U-shaped part by a powerful elastic force produced from the abutment of the membrane soft hinge part and the V-shaped elastic body, thus to drive the protection cover to automatically lock the needle head and prevent the needle head pressed in the protection cover from being rejected, i.e., the used syringe cannot be reused.本創作提供一種安全注射針裝置,包括注射針筒,針頭裝置、作動主體部及保護套;作動主體部,包括固定U形部、活動U形部、薄膜軟質絞鏈部及通口,兩U形部間以薄膜軟質絞鏈部連接,並藉通口處兩端所連接之V形彈性體,提供兩U形部在進行相對彎折翻轉時有足夠的彈性作用力,又藉活動U形部末端之受插部與保護套前端之插接部相連結,使注射針筒在丟棄前將保護套往針頭方向撥動,藉薄膜軟質絞鏈部及V形彈性體靠合之強大彈力使活動U形部及保護套得以向固定U形部彎折轉動,使保護套自動鎖合針頭,且使針頭被壓入保護套內而無法再退出,杜絕被再度使用之虞。10‧‧‧注射針筒11‧‧‧針筒12‧‧‧針筒接頭121‧‧‧通孔13‧‧‧活塞推桿20‧‧‧針頭裝置21‧‧‧針頭座22‧‧‧針頭支撐套23‧‧‧針頭30‧‧‧作動主體部31‧‧‧固定U形部32‧‧‧活動U形部33‧‧‧薄膜軟質絞鏈部330‧‧‧通口34‧‧‧受插部341‧‧‧接部插孔35‧‧‧V形彈性體351‧‧‧長邊352‧‧‧短邊40‧‧‧保護套41‧‧‧基板42‧‧‧側板421‧‧‧護條422‧‧‧撥動部43‧‧‧端板44‧‧‧套置空間45‧‧‧插接部451‧‧‧裂槽
