Machine Tool Servo Excitation Control for Lower Idle Power
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Solution Overview
Problem
Machine tools consume excessive energy due to continuous excitation of servo motors, despite some motors not being actively used during machining, which contradicts the growing demand for energy efficiency.
Innovation Solution
Classify servo motors into continuous and intermittent drive motors, and selectively stop excitation of intermittent motors during machining using a numerical controller with a motor classification unit and stop control unit, while ensuring safety and preventing delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If servo motors are continuously excited to maintain readiness, then operational reliability is improved, but power consumption increases
Solution Approach 1:
The patent applies dynamics by transitioning servo motors between excited and unexcited states based on real-time machining requirements. The control unit dynamically adjusts motor states - keeping motors excited when machining operations are active and stopping excitation when motors are idle, thereby adapting the system's energy state to operational demands while maintaining reliability.
Solution Approach 2:
The patent implements periodic action by cycling servo motor excitation on and off based on machining program phases. Motors are excited periodically during machining operations and unexcited during idle periods, creating a rhythmic pattern of energy consumption that aligns with operational requirements rather than continuous excitation.
2Speed
If all servo motors remain excited during machining, then response time is improved, but energy efficiency deteriorates
Solution Approach 1:
The control unit performs preliminary action by predicting when motors will be needed based on the machining program schedule. It maintains motor excitation only during periods when machining operations are imminent or ongoing, and stops excitation in advance of idle periods, thereby preparing the system for upcoming operations while avoiding unnecessary energy consumption during known idle times.
3Use of energy by moving object
If servo motors are stopped during idle periods, then power consumption is reduced, but operational delays may occur
Solution Approach 1:
The control unit employs feedback by continuously monitoring the machining program execution state and motor operational requirements. It uses this feedback information to make real-time decisions about maintaining or stopping motor excitation, ensuring that motors are kept excited only when actually needed for machining operations, thereby preventing both energy waste and operational delays.
Data Source
AI summary
A machine tool according to an aspect of the present disclosure comprises: a plurality of servo motors; a plurality of servo amplifiers that drive the servo motors, respectively; and a numerical value control device that inputs a command value to the plurality of servo amplifiers in accordance with a processing program. The numerical value control device has: a motor classification unit that classifies the plurality of servo motors into continuous drive motors which require continuous excitation during execution of the processing program and intermittent drive motors in which excitation can be stopped at least temporarily during the execution of processing program; and a stop control unit that stops the excitation of at least one of the intermittent drive motors during the execution of the processing program.