Tool adapter for narrow space machining

The invention discloses a tool adapter for narrow space machining. The tool adapter for narrow space machining comprises an upper cover plate and a lower cover plate distributed up and down. The rightends of the upper cover plate and the lower cover plate are fixedly connected to the lower end of a sleeve; a first gear, a second gear and a third gear are successively arranged from right to left on the top of the lower cover plate; the center position of the first gear is fixedly connected to the lower end of a cylindrical rod; the upper end of the cylindrical rod is fixedly connected to the lower part of a handle; the handle is in pivot connection to the inner side of the end surface of a spindle of a machine tool; the lower part of the end surface of the spindle of the machine tool is fixedly connected to the upper part of the sleeve; an upper boss of the third gear is fixedly connected to a first cutterhead through a fourth screw; a center shaft of the third gear is arranged in thecenter position of the thi