Dental external suction arm

The suction arm (1) comprises a first arm part (11) which is connected with the front end part of a fixing rod (10) vertically arranged on a floor through a first joint (21), rotates around the first joint (21) and tilts from a vertical state. The first arm section (11) is provided with a reaction force mechanism (3) that applies a reaction force to the first arm section (11) in the direction in which the first arm section (11) returns to the standing state when the first arm section (11) is tilted. The reaction force mechanism (3) nonlinearly increases the reaction force with respect to an increase in the tilt angle of the first arm section (11). 吸引臂(1)包括：第一臂部(11)，其经由第一关节(21)与竖立设置于地板上的固定用杆(10)的前端部连结，以第一关节(21)为中心转动而从立起状态倾倒。第一臂部(11)具备反作用力机构(3)，反作用力机构(3)在第一臂部(11)倾倒时，对第一臂部(11)向恢复到立起状态的方向赋予反作用力。反作用力机构(3)使反作用力相对于第一臂部(11)的倾倒角度的增加非线性地增加。