Detection device for detection of workpiece axis diameter and jerk value

The present invention discloses a device for detection of a workpiece axis diameter and a jerk value. The device comprises: a tip configured to tightly press the end portion of a workpiece; a cylinder, wherein the tip is fixed in an axial direction relative to the piston of the cylinder and is capable of circumferential rotating; a motor configured to drive the rotation of the tip; a displacementsensor assembly comprising a touch rod, a spring configured to tightly press the touch rod at a detection point of the workpiece and allow the touch rod to float with the bounce of the workpiece or the change of the size of an axle journal and a slide plate moved with the floating of the touch rod to allow the displacement sensor assembly to output different electrical signals; a controller configured to receive electrical signals of the displacement sensor assembly and convert the electrical signals to the axis diameter size value or the jerk value of the workpiece; and a display device, wherein the controller output