Injection needle assembly and drug injection device

Abstract

Objects are to ensure a required depressing force and puncture speed when a needle tube is punctured in the skin, and to be able to reliably situate a needle tip of a needle tube in the upper layer of skin. A needle injection assemblyincludes a needle tubehaving a needle tipthat can be punctured in a living body, a hubthat holds the needle tube, an adjustment section, a stabilizing section, and a puncture speed securing member. The adjustment sectionis provided around the periphery of the needle tubeand has a needle projection surface, from which the needle tipof the needle tubeprojects. The stabilizing sectionextends from the hub, is disposed to surround the needle tubeand has an end facethat comes in contact with the skin when the needle tubeis punctured in the living body. The puncture speed securing member is provided at the adjustment sectionor stabilizing sectionsuch that the puncture speed securing member moves along the axial direction of the needle tube. The puncture speed securing memberis brought into contact with the skin ahead of the needle tipof the needle tubewhen the needle tubeis punctured in the living body and ensures the speed and depressing force as desired when the needle tubeis punctured in the living body.