Abstract
Achieving geometrical accuracy in cylindrical traverse grinding for high-aspect slender parts is still a challenge due to the flexibility of the workpiece and, therefore, the resulting shape error. This causes a bottleneck in production due to the number of spark-out strokes that must be programmed to achieve the expected dimensional and geometrical tolerances. This study presents an experimental validation of a shape-error prediction model in which a distributed load, corresponding to the grinding wheel width, is included, and allows inclusion of the effect of steady rests. Headstock and tailstock stiffness must be considered and a procedure to obtain their values is presented. Validation of the model was performed both theoretically (by comparing with FEM results) and experimentally (by comparing with the deformation profile of the real workpiece shape), obtaining differences below 5%. Having determined the shape error by monitoring the normal grinding force, a solution was presented to correct it, based on a cross-motion of the grinding wheel during traverse strokes, thus decreasing non-productive spark-out strokes. Due to its simplicity (based on the shape-error prediction model and normal grinding force monitoring), this was easily automatable. The corrective compensation cycle gave promising results with a decrease of 77% in the shape error of the ground part, and improvement in geometrically measured parameters, such as cylindricity and straightness.
Highlights
Published: 9 December 2021Grinding is an abrasive machining process carried out in the last step of manufacturing due to its capability to obtain smooth surfaces and precise geometrical tolerances.Traverse grinding is an extended type of the cylindrical grinding process used for parts such as electric motor shafts, pneumatic cylinders and hydraulic cylinders and is based on the kinematics of plunge grinding with a cross-feed motion parallel to the workpiece axis
This study is focused on the shape error of slender parts because shape form for these parts must be very accurate
Metals 2021, 11, 1990 headstock-center eccentricity must be considered to determine the shape error in slender parts have demonstrated thatthat the main causecause of workpiece deformation parts[5]
Summary
Grinding is an abrasive machining process carried out in the last step of manufacturing due to its capability to obtain smooth surfaces and precise geometrical tolerances. Traverse grinding is an extended type of the cylindrical grinding process used for parts such as electric motor shafts, pneumatic cylinders and hydraulic cylinders and is based on the kinematics of plunge grinding with a cross-feed motion parallel to the workpiece axis. This process comes with several non-controlled variables that change during the operation, producing defects in the workpiece topography [1], including shape errors [1]. Metals 2021, 11, 1990 headstock-center eccentricity must be considered to determine the shape error in slender parts have demonstrated thatthat the main causecause of workpiece deformation parts[5].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have