Principle and advantageous features of eddy current detection in CNC roll grinding machines
CNC roll grinder eddy current detection principle for the detection of conductive materials, the conductor close to the coil with alternating current, the coil to establish an alternating magnetic field, the alternating magnetic field through the conductor, and electromagnetic induction with the role of the conductor to establish eddy currents in the conductor. The eddy currents in the conductor also generate their own magnetic field, and the action of the eddy current magnetic field changes the strength of the original magnetic field. This in turn leads to changes in coil voltage and impedance.
The eddy current flaw detection of CNC roll grinder has the following advantages:
1, can detect rolls made of various metals;
2, can detect the surface opening cracks, soft spots, inclusions;
3, low quality requirements on the surface of the roll, not subject to water, oil interference;
4, can be grinding while detecting, improve grinding efficiency. But eddy current flaw detection also has limitations:
5, can only detect roll surface cracks, can not detect deep cracks within the roll;
6, can only show the relative severity of cracks, can not show the specific depth of cracks;
7, the roll surface if there is magnetic interference with the results of flaw detection.
The CNC roll grinding machine equipment mainly includes one set each of bed, guideway, roll drive system, grinding head stand, cross feed and up and down feed mechanism, grinding spindle integration system, grinding tool, round trip drive system, grinding wheel dresser series, grinding wheel wear compensation, dust suction device, electrical cabinet, automatic lubrication, full set of electrics, CNC control system, profiling device, protection system, automatic approach system, etc. The machine is equipped with a servo motor, a servo motor, a servo motor, a servo motor, a servo motor, a servo motor, a servo motor and a servo motor. The rolls are driven by servo motors with stepless variable range of 0.5 to 200rpm, and can be rotated clockwise and counterclockwise, forward and backward. The tailstock is longitudinally adjustable, and the tailstock is vertical, adjusted for erosion errors. The fixture for holding and grinding the rolls is driven by a center ring.