CNC Compound Machining for Thermal Damage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional machining processes are limited by the need for specialized machines for each process type, and computer numerically controlled (CNC) machines struggle to efficiently manage relative velocities between tools and workpieces, leading to reduced processing power and increased torque, which can result in thermal damage and machine downtime.
Innovation Solution
A CNC machine operates by rotating both the workpiece and tool at high surface velocities, allowing for compound machining operations where the relative velocity is determined algorithmically, enabling increased processing power without excessive torque and facilitating the removal of discrete chips, thus reducing downtime and allowing for the creation of knurled-like patterns on workpieces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional machining processes use specialized machines for each process type, then machining precision and reliability are maintained, but device complexity and loss of time increase due to multiple machines and setup changes
Solution Approach 1:
The patent implements a universal CNC machine capable of performing multiple machining operations (turning, milling, drilling, threading, knurling) on a single workpiece without requiring separate specialized machines. The machine includes a main spindle for rotating the workpiece and a tool spindle for holding and moving cutting tools, enabling diverse machining functions through software control and tool selection rather than requiring different physical machines for each operation type.
2Productivity
If CNC machines increase relative velocity between tool and workpiece to enhance processing power, then productivity improves, but torque increases causing thermal damage and machine downtime
Solution Approach 1:
The patent dynamically adjusts the rotational speeds of both the main spindle (workpiece) and tool spindle during machining operations. By independently controlling the rotation speeds of both spindles, the system optimizes the relative velocity between tool and workpiece to achieve high material removal rates while maintaining torque within safe limits, preventing thermal damage to the workpiece and machine components.
Solution Approach 2:
The system changes multiple parameters simultaneously - the rotational speed of the main spindle, the rotational speed of the tool spindle, and the feed rate - to optimize machining performance. By algorithmically determining combinations of these parameters, the machine achieves high processing power without excessive torque, as the increased workpiece rotation speed compensates for reduced tool engagement time, allowing faster material removal with lower instantaneous loads.
3Speed
If conventional turning machines rotate workpiece at high velocity with tool moving at low velocity, then cutting speed is achieved, but processing power is limited and discrete chip removal is difficult
Solution Approach 1:
The patent transforms the conventional machining model by making both the workpiece and tool rotate during machining operations. The main spindle rotates the workpiece at high speed while the tool spindle rotates the cutting tool, creating dynamic relative motion that enhances cutting performance. This dual rotation enables higher effective cutting speeds and greater processing power compared to conventional methods where only one component rotates.
Solution Approach 2:
Instead of the conventional approach where the tool moves linearly against a rotating workpiece, the patent inverts the motion model by having both workpiece and tool rotate. This inversion allows the cutting action to occur through the relative rotation of both components, enabling higher material removal rates and better chip evacuation through the combined rotational motion and associated centrifugal forces.
4Adaptability or versatility
If mill/turn machines substitute workpiece rotation at low velocity for linear feed, then milling capability is added, but processing power and efficiency are reduced
Solution Approach 1:
The patent enhances the mill/turn capability by implementing high-speed rotation of the workpiece on the main spindle during milling operations, rather than using low-velocity rotation as in conventional mill/turn machines. The tool spindle provides controlled tool motion while the rapidly rotating workpiece enables high-speed milling, significantly increasing processing efficiency while maintaining the versatility to perform both turning and milling operations on the same machine.
Data Source
AI summary
A method of machining a workpiece may include continuously rotating the workpiece, continuously rotating a tool having at least one cutting surface, and positioning the tool relative to the workpiece so that the at least one cutting surface engages the workpiece at a first discrete location at a periphery of the workpiece. The method may further include continuing to rotate the workpiece and the tool so that the at least one cutting surface engages a second discrete location at the periphery of the workpiece, and controlling a tool surface velocity VT relative to the workpiece surface velocity VW so that the first and second discrete locations are discontinuous. The tool may make multiple iterative passes over the workpiece to engage subsequent discrete locations, wherein the first discrete location, second discrete location, and multiple subsequent discrete locations may form a machined surface that extends continuously around the workpiece.