Patent ID: 7632251

Claim:
A volume-adjustable micro-injection device, comprising: a base structure having a syringe positioning structure for receiving an injection syringe and at least a pistol-like grip composed of a left case and a right case for a user's hand to hold and operate; a holding structure having an angle adjustment knob, a fastener and an angle tenon located at a first end portion of said syringe positioning structure, wherein the angle adjustment knob has a first end portion for mounting the syringe thereto and a second end portion for connecting an injection needle thereto in a movable manner, and the angle adjustment knob is tightly fitted with the fastener and has a polygonal body with a plurality of urging sides urged and fixed by the angle tenon after a rotational adjustment; a pressure pushing structure located at a second end portion of said syringe positioning structure and connected with said base structure; an eject structure integrated with said base structure and located in the proximity of said pressure pushing structure; an injection controller integrated with said base structure and driving said pressure pushing structure through a drive structure to exert pressure on a plunger of said injection syringe; and a qualitative controller including a dose control knob, a control knob positioning member and a positioning spring interlinked with said injection controller to control an allowable displacement of said pressure pushing structure, wherein the control knob positioning member is pivotally disposed in the base structure and a movable end portion thereof is driven by the positioning spring to constantly push against the dose control knob.