Spindle Axis Control for Tapping Cycle Time and Shock Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In machine tools performing tapping processes with synchronized spindle and feed axis operations, existing technologies face challenges in reducing cycle time while minimizing mechanical or structural shocks and synchronization errors caused by acceleration changes.
Innovation Solution
A controller is configured to manage the spindle axis' rotational motion by preparing and executing commands for accelerated and decelerated rotations, using maximum permissible current and detecting real-time acceleration and speed to optimize deceleration strategies, thereby reducing shocks and errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the spindle axis is controlled to maximize acceleration capacity, then cycle time is reduced, but mechanical or structural shock increases due to acceleration changes
Solution Approach 1:
The patent segments the acceleration process into multiple stages with different acceleration rates. Instead of applying maximum acceleration uniformly, the control device divides the acceleration period into several phases, each with progressively increasing acceleration, thereby reducing sudden shock while still achieving maximum cycle time reduction.
Solution Approach 2:
The patent implements dynamic acceleration control where the acceleration rate is continuously adjusted based on real-time feedback from acceleration detectors and position detectors. The system dynamically modifies the acceleration profile during operation to optimize between cycle time and shock reduction.
2Productivity
If the spindle axis is controlled to maximize acceleration capacity, then cycle time is reduced, but synchronization error increases between spindle axis and feed axis
Solution Approach 1:
The patent employs feedback control mechanisms where detectors continuously monitor the rotational position of the spindle axis and the position of the feed axis. The control device uses this feedback information to dynamically adjust acceleration commands, ensuring that synchronization is maintained even during maximum capacity acceleration, thereby reducing synchronization errors.
Solution Approach 2:
The patent performs preliminary calculation and preparation of acceleration profiles based on the detected rotational speed and acceleration characteristics of the spindle axis. By pre-planning the acceleration sequence according to actual machine characteristics, the system ensures synchronized operation between axes while maximizing acceleration capacity.
3Manufacturing precision
If feed command value is corrected based on actual rotational position, then tapping accuracy is improved, but device complexity increases
Solution Approach 1:
The patent implements a self-correcting control system where the control device automatically adjusts feed command values based on feedback from position detectors and acceleration detectors. The system uses its own operational data to self-regulate and maintain accuracy without requiring external intervention or complex manual adjustments.
Data Source
AI summary
A controller controlling a synchronized operation of spindle and feed axes. A positioning-motion control section of a spindle-axis control section calculates a first velocity command making a spindle axis perform a decelerated rotation at a variable deceleration lower than a maximum deceleration during an acceleration-varying time just after the spindle axis reaches an intermediate speed or just before the spindle axis reaches a target position, and making the spindle axis perform the decelerated rotation at the maximum deceleration during a time except for the acceleration-varying time; calculates a second velocity command making the spindle axis perform a decelerated rotation at a constant deceleration lower than the maximum deceleration after the spindle axis reaches the intermediate speed; and chooses either one, achieving a lower speed, of the first and second velocity command during a period when the spindle axis operates from the intermediate speed to reach the target position.