Finishing Tool Infeed Control for Rotationally Symmetrical Workpieces
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Solution Overview
Problem
The grinding process in the machining of rotationally symmetrical workpieces often results in shape defects such as small-order ripples (polygons) that cannot be eliminated by conventional finishing methods, requiring lengthy pre-processing times and increased costs due to the need for precise feed parameter control to achieve desired surface quality.
Innovation Solution
A finishing method that controls the infeed path of the finishing tool based on a force signal proportional to the pressing force, allowing for position control and incremental infeed movements to address both micro-form and macro-form errors, thereby reducing the reliance on precise grinding and shortening processing times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the feed parameters during grinding are limited to relatively low values to avoid form defects and achieve required concentricity, then the manufacturing precision is improved, but the productivity deteriorates due to relatively long pre-machining time
Solution Approach 1:
The invention performs preliminary shaping actions during the finishing process itself. The finishing tool is fed in a controlled manner to deliberately create specific geometric features (such as cross-hatch patterns) that simultaneously achieve both surface finish improvement and form correction, eliminating the need for separate preliminary operations to correct form defects.
Solution Approach 2:
The invention employs periodic oscillation of the finishing tool or workpiece during the finishing process. This periodic motion creates varying contact conditions that allow the finishing tool to progressively correct form errors while maintaining material removal rates, thereby improving both precision and productivity.
2Manufacturing precision
If conventional finishing methods are used after grinding, then the surface finish is improved, but the form defects such as small-order ripples cannot be eliminated, requiring increased pre-processing time
Solution Approach 1:
The invention merges the functions of form correction and surface finish improvement into a single finishing operation. The finishing process is designed to simultaneously address both macro-form errors (such as polygons) and micro-form errors (surface roughness), eliminating the need for multiple separate operations and reducing total processing time.
Solution Approach 2:
The invention introduces dynamic control of the finishing process parameters, including variable feed rates and oscillation amplitudes, to adapt to different stages of form correction. This dynamic approach allows the process to efficiently address both form errors and surface finish requirements without time loss.
3Manufacturing precision
If the grinding process is designed to achieve desired overall concentricity without form defects, then the manufacturing precision is improved, but the device complexity increases due to precise feed parameter control requirements
Solution Approach 1:
The invention employs self-regulating mechanisms in the finishing process where the tool automatically adjusts its effective feed rate based on workpiece geometry and contact conditions. This self-service approach reduces the need for complex external control systems while maintaining high concentricity and form accuracy.
Solution Approach 2:
The invention incorporates feedback mechanisms that monitor the finishing process in real-time and automatically adjust process parameters to maintain optimal concentricity. This feedback control simplifies the overall system by using intelligent regulation rather than complex pre-programmed feed schedules.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables cost optimization of the grinding-finishing process chain by improving the roundness and reducing form errors, allowing for the same final quality of machined workpieces with reduced pre-processing times and enhanced surface finish.
Implementation Method 1
a finishing tool (finishing stone or finishing strip) coated with abrasive material is pressed against the surface to be machined
Implementation Method 2
pressing an abrasive finishing belt against the workpiece section with a defined pressure force (e.g., between 50 N and 500 N) using a pressure device
Implementation Method 3
the workpiece is rotated around its axis. In some finishing process variations, a relative oscillation parallel to the workpiece axis is simultaneously generated
Data Source
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AI summary
In a finishing method for finish machining a rotationally symmetrical workpiece section on a workpiece, the workpiece is rotated for the finish machining about a workpiece axis and, in a workpiece section to be machined, a finishing tool equipped with cutting means is pressed with a contact pressure force against a circumferential surface of the workpiece section. In the process, a force signal proportional to the contact pressure force is determined, and a feed path of the finishing tool is controlled during at least one phase of the finishing method on the basis of the force signal.