Torque-Based Drilling Control for Layered Workpiece Quality

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Drilling work in layered products with materials of different qualities is inefficient due to the need for manual adjustment of working conditions for each layer, leading to reduced efficiency and potential quality issues like burrs and delamination.

Innovation Solution

A drilling work control method and device that automatically discriminates between layers based on load torque variations, adjusting spindle speed and feeding speed for each layer to optimize drilling conditions and reduce tool wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manual adjustment of working conditions is performed for each layer, then drilling quality is maintained, but drilling efficiency decreases

Engineering Contradiction:
Improvedrilling qualityVSAvoiddrilling efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The drilling system automatically detects layer transitions by monitoring torque variations and autonomously adjusts working conditions without manual intervention. The control unit self-regulates spindle speed and feed rate based on real-time torque data, enabling the system to serve itself in maintaining drilling quality across different layers while improving efficiency.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system continuously monitors torque during drilling and uses this feedback to detect layer transitions. When torque variation exceeds a threshold indicating a layer change, the control unit automatically adjusts working conditions. This closed-loop feedback mechanism ensures drilling quality is maintained while eliminating manual adjustment time.

Inventive Principle:
Principle #23Feedback

2Productivity

If drilling speed is increased for efficiency, then productivity improves, but tool wear and workpiece quality deteriorate

Engineering Contradiction:
Improvedrilling speedVSAvoidworkpiece quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts spindle speed and feed rate based on real-time torque monitoring and layer detection. Instead of using a fixed high speed, the drilling parameters are continuously optimized according to the current layer's material properties, allowing high productivity while preventing tool wear and quality deterioration through adaptive speed control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit changes drilling parameters (spindle speed, feed rate) based on detected layer transitions. When a layer change is detected through torque variation, the system automatically adjusts parameters to match the new material's optimal drilling conditions, maintaining workpiece quality and tool life while preserving overall drilling efficiency.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If working conditions are standardized for all layers, then operation simplicity increases, but drilling quality and tool life decrease

Engineering Contradiction:
Improveoperation simplicityVSAvoiddrilling quality
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The system eliminates the need for manual working condition selection by implementing automatic layer detection and parameter adjustment. The control unit autonomously determines optimal working conditions for each layer based on torque monitoring, providing both operational simplicity and drilling quality without requiring user expertise in selecting parameters for different materials.

Inventive Principle:
Principle #25Self-service

4Measurement precision

If layer discrimination is performed manually, then working condition accuracy is maintained, but time consumption and cost increase

Engineering Contradiction:
Improvelayer discrimination accuracyVSAvoidtime consumption
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system replaces manual layer discrimination with automatic torque-based detection. By monitoring torque variations during drilling, the control unit automatically identifies layer transitions without requiring manual inspection or intervention. This substitution maintains accurate layer discrimination while eliminating the time consumption and labor costs associated with manual methods.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Improves drilling efficiency by automating layer recognition and adjusting drilling parameters, enhancing the quality of the workpiece by reducing burrs and delamination, and lowering the cost of the drilling device.

Implementation Method 1

a load torque detecting means that detects a load torque applied to the drill

Methodology Applied
Scientific EffectLoad torque detection: Torque

Data Source

PatentEP2591870B1Drilling work control method and drilling work device
Publication Date: 2021.03.31 MITSUBISHI HEAVY IND LTD
  • EP2591870B1 patent drawingFigure 1(a)~1(b)
  • EP2591870B1 patent drawingFigure 2(a)~2(c)
  • EP2591870B1 patent drawingFigure 3

AI summary

[Problem] To enable to automatically discriminate two or more working object layers where a hole is formed based on load torque applied to a drill in order to form the hole in a workpiece that includes plural forming areas divided by being formed of materials of different qualities, to achieve to facilitate drilling work in a working condition set for each working object layer, and to improve the working efficiency. [Solution] In a drilling work device that forms the hole 70 in the workpiece 50 having forming layers 51 to 56 divided by the materials of different qualities, working object layer determining means determines the working object layers 51a to 56a in order of drilling work based on start of drilling work and variation in the load torque applied to the drill 4, working condition deciding means decides a set working spindle speed and a set working feeding speed corresponding to forming materials of the respective working object layers 51a to 56a, and drive controlling means controls a spindle motor and a feeding motor so that the drill 4 forms the hole 70 at the set working spindle speed and the set working feeding speed.