Bobbin replacing device of spinning frame

The invention provides a bobbin replacing device of a spinning frame, which can reduce the rotation amount of a scaling mechanism accompanying the thermal expansion of a rod. A ring spinning frame (10) is provided with a spinning machine table (11); a scaling mechanism (21) that lifts and lowers a doffing rod (20) provided with a bobbin holding device; a driving shaft (22) the axis of which (22) extends in the long side direction of the thread spinner table, and which drives the scaling mechanism; a power cylinder (27) that reciprocates the drive shaft; and a rotating mechanism which enables the whole zooming mechanism to rotate towards a position close to the spinning machine table (11) and a position far away from the spinning machine table. The rotation mechanism is provided with a first rod (29) and a second rod (30) that reciprocate in the longitudinal direction of the textile machine table; a first cylinder (31) that reciprocates the first rod; a second cylinder (32) that reciprocates the second rod; a