Hole Processing Spindle Control Using Cutting Resistance Feedback

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Solution Overview

Problem

Conventional handheld tool driving devices for hole processing require users to manually determine and adjust the rotating speed and feeding speed of tools based on tool diameter, workpiece material, and material thickness, making it difficult to achieve suitable processing conditions, especially when dealing with laminated materials.

Innovation Solution

A tool driving device equipped with a spindle, electric motor, guide, electric actuator, sensor, and controller that adjusts rotating speed and feeding speed based on cutting resistance measured by the sensor, allowing for automatic control of these parameters during hole processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a user manually determines rotating speed and feeding speed based on tool diameter and workpiece material, then the device structure remains simple, but the processing quality deteriorates when dealing with laminated materials or when user knowledge is insufficient

Engineering Contradiction:
Improvehole processing qualityVSAvoiddevice structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements feedback control by measuring cutting resistance during hole processing and automatically adjusting rotating speed and feeding speed based on the measured values. The sensor detects cutting resistance in real-time, and the controller modifies processing parameters dynamically to maintain optimal processing conditions across different materials and depths, thereby ensuring high processing quality without requiring complex manual determination by the user.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment of processing parameters by automatically controlling the rotating speed and feeding speed based on measured cutting resistance. The controller independently modifies motor speeds without requiring user intervention or prior knowledge of appropriate parameters for different materials, enabling the device to serve itself in determining optimal processing conditions.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If the device allows independent setting of rotating speed and feeding speed, then processing adaptability improves, but the ease of operation deteriorates due to the need for advance parameter determination

Engineering Contradiction:
Improveprocessing condition adaptabilityVSAvoidparameter setting ease
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The feedback mechanism automatically determines appropriate rotating speed and feeding speed by measuring cutting resistance during processing. The sensor continuously monitors cutting conditions and the controller adjusts motor speeds accordingly, eliminating the need for users to manually determine and set parameters in advance while maintaining full adaptability to different workpiece materials and conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system autonomously determines and adjusts processing parameters without requiring user input or knowledge. The controller self-manages the independent control of rotating speed and feeding speed by interpreting sensor data and automatically modifying motor speeds, thereby providing both adaptability and ease of operation simultaneously.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If the device requires changing rotating speed or feeding speed when material changes occur, then processing precision is maintained, but the productivity deteriorates due to manual intervention time

Engineering Contradiction:
Improveprocessing precisionVSAvoidhole processing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The feedback control system continuously monitors cutting resistance during hole processing through the sensor. When the tool encounters different materials or material boundaries, the cutting resistance changes are detected in real-time, and the controller automatically adjusts rotating speed and feeding speed without requiring manual intervention. This maintains processing precision while eliminating time losses associated with manual parameter changes, thereby improving productivity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The automatic feedback control enables continuous processing without interruption. The sensor continuously monitors cutting conditions, and the controller continuously adjusts processing parameters, ensuring that the useful action of hole processing proceeds without pause or manual intervention even when material properties change, thereby maintaining both precision and high productivity.

Inventive Principle:
Principle #20Continuity of useful action

4Measurement precision

If a sensor measures cutting resistance in real-time, then processing control accuracy improves, but the device complexity increases

Engineering Contradiction:
Improvecutting resistance measurement accuracyVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor measures cutting resistance in real-time during hole processing, providing accurate feedback to the controller. This measurement capability enables precise automatic adjustment of rotating speed and feeding speed based on actual cutting conditions, significantly improving measurement and control accuracy while adding only minimal device complexity through the integration of a single sensor and control algorithm.

Inventive Principle:
Principle #23Feedback

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

Enables users to perform hole processing with appropriate rotating and feeding speeds without prior knowledge, ensuring high-quality results even with laminated materials by automatically adjusting speeds based on real-time thrust resistance measurements.

Implementation Method 1

The sensor measures cutting resistance transmitted from the tool to the spindle

Methodology Applied
Scientific EffectForce measurement: Force

Implementation Method 2

The electric motor rotates the spindle

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 3

The electric actuator advances and retreats the spindle relatively to the guide in a rotation axis direction of the spindle

Methodology Applied
Scientific EffectElectromechanical actuation: Linear Motor

Data Source

PatentEP4331759A1Tool driving device and method of producing hole processed product
Publication Date: 2024.03.06 SUBARU CORP
  • EP4331759A1 patent drawingFigure 1
  • EP4331759A1 patent drawingFigure 2
  • EP4331759A1 patent drawingFigure 3~4

AI summary

A tool driving device (1) for hole processing includes a spindle (3), an electric motor (4), a guide (6), an electric actuator (7), a sensor (31) and a controller (8). The spindle (3) has a holder (2) for holding a tool (T) for the hole processing. The holder (2) is disposed at a distal portion of the spindle (3). The electric motor (4) rotates the spindle (3). The guide (6) has a positioning member (5) for positioning the tool driving device (1) to the workpiece (W). The electric actuator (7) advances and retreats the spindle (3) relatively to the guide (6) in a rotation axis direction of the spindle (3). The sensor (31) measures cutting resistance transmitted from the tool (T) to the spindle (3). The controller (8) is configured to control the electric motor (4) and the electric actuator (7) based on the cutting resistance measured by the sensor (31) so that a rotating speed and a feeding speed of the spindle (3) become a rotating speed and a feeding speed according to the cutting resistance.