Vibration Cutting Amplitude Control for Precise Tool Stopping
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Solution Overview
Problem
Conventional machine tools fail to prevent the cutting tool from vibrating beyond a predetermined stopping position, leading to potential over-cutting of the workpiece.
Innovation Solution
Incorporating an amplitude control unit that reduces the reciprocal vibration amplitude when the cutting tool reaches the stopping position, ensuring the cutting tool does not exceed the intended cutting area by synchronizing the forward and backward vibration movements and gradually adjusting the amplitude as the cutting tool approaches the stopping point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the cutting tool performs reciprocal vibration cutting to machine the workpiece, then the cutting efficiency and chip separation are improved, but the cutting tool may exceed the predetermined stopping position and cause over-cutting
Solution Approach 1:
The patent applies dynamics by making the vibration amplitude variable rather than constant. The amplitude control unit dynamically adjusts the vibration amplitude during the cutting process, reducing it as the cutting tool approaches the stopping position. This resolves the contradiction by allowing high amplitude vibration for efficient cutting most of the time, then transitioning to low amplitude for precise stopping, thus maintaining both productivity and precision.
Solution Approach 2:
The patent changes the parameter of vibration amplitude from a fixed value to a variable that changes during the cutting process. By controlling the amplitude to decrease as the cutting tool nears the stopping position, the system maintains high cutting efficiency during the majority of the cut while ensuring precise positioning at the end. This parameter change strategy directly addresses the contradiction between cutting efficiency and positioning precision.
2Loss of time
If the cutting tool continues vibration cutting without amplitude reduction, then the cutting work is completed quickly, but the cutting tool exceeds the predetermined stopping position
Solution Approach 1:
The patent implements periodic action by using reciprocal vibration with varying amplitude. The vibration continues periodically to maintain cutting efficiency, but the amplitude modulates based on the cutting tool's position relative to the stopping point. This allows the cutting process to remain time-efficient while achieving accurate stopping through amplitude control near the endpoint.
Solution Approach 2:
The amplitude control unit performs preliminary action by anticipating the stopping position and beginning to reduce vibration amplitude before the cutting tool actually reaches the stopping point. This proactive amplitude reduction prevents overshooting while maintaining efficient cutting throughout the process, thus minimizing time loss without sacrificing positioning accuracy.
3Manufacturing precision
If the vibration amplitude is reduced near the stopping position, then the cutting precision is improved, but the cutting speed decreases
Solution Approach 1:
The system uses dynamic amplitude adjustment where the vibration amplitude is high during most of the cutting process to maintain high cutting speed, then transitions to low amplitude only when approaching the stopping position. This dynamic adaptation resolves the contradiction by optimizing for speed during the majority of the cut and for precision only when necessary near the endpoint.
Solution Approach 2:
The patent applies partial action by reducing vibration amplitude only for the final portion of the cutting stroke near the stopping position, rather than reducing it throughout the entire cut. This partial application of amplitude reduction maintains high cutting speed for the majority of the work while achieving sufficient precision for the critical stopping phase.
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
Prevents cutting beyond the predetermined stopping position, allowing for smooth finishing of the workpiece surface and effective chip separation during the cutting process.
Implementation Method 1
a vibration unit to relatively vibrate the work holding unit and the tool rest so that the cutting tool is fed in the feeding direction while reciprocally vibrating in the feeding direction
Implementation Method 2
an amplitude control unit to control an amplitude of the reciprocal vibration by the vibration unit, and the amplitude control mean is configured to reduce the amplitude of the reciprocal vibration
Data Source
AI summary
A machine tool and a control apparatus thereof include an amplitude control unit to control the amplitude of reciprocal vibration by a vibration unit. The amplitude control unit is configured to reduce the amplitude of the reciprocal vibration by the vibration unit as a cutting tool is fed in a feeding direction when the cutting tool reaches a predetermined cutting tool work stopping position on a workpiece in the feeding direction (Z-axis direction) to prevent the cutting tool from cutting the workpiece beyond the cutting tool work stopping position.