Adaptive Core Drill Speed Control for Stable Spot Drilling

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Solution Overview

Problem

Hand-held core drilling machines face challenges in maintaining efficient and safe operation due to user fatigue and varying operating conditions, leading to difficulties in the initial drilling phase and overall core drilling process.

Innovation Solution

A method for controlling a machine tool that adjusts drive speed based on power consumption thresholds, allowing for increased speed when load exceeds a defined value, dependent on duration and magnitude of exceeding, to compensate for changing conditions and maintain constant drilling progress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the drive speed is increased to maintain drilling progress, then productivity is improved, but the drive power consumption increases excessively

Engineering Contradiction:

Improvedrilling progressVSAvoiddrive power consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The drive speed is made dynamically adjustable based on real-time power consumption measurements. The control unit continuously monitors power consumption and adapts the drive speed accordingly, transitioning from a static speed setting to a dynamic control system that responds to changing load conditions during drilling operations.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the drive speed parameter in response to measured power consumption values. When power consumption exceeds the threshold, the control unit reduces the drive speed to maintain safe operating limits, and when power consumption is within limits, the drive speed is increased to maintain drilling progress.

Inventive Principle:

Principle #35Parameter changes

2Power

If the contact pressure on the tool is increased to achieve higher drive power, then drilling efficiency is improved, but the drive power consumption increases

Engineering Contradiction:

Improvedrive powerVSAvoiddrive power consumption

Core Design Contradiction:

PowerVSUse of energy by moving object

Solution Approach 1:

The system implements a feedback mechanism where the control unit continuously measures power consumption and uses this information to regulate drive power. The measured power consumption serves as feedback that triggers control actions to maintain drive power within safe operating limits while maximizing drilling efficiency.

Inventive Principle:

Principle #23Feedback

3Productivity

If the drive speed is constantly increased to maintain drilling progress, then productivity is improved, but the risk of overheating and damage increases

Engineering Contradiction:

Improvedrilling progressVSAvoidrisk of overheating and damage

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system prepares for potential overheating and damage by establishing a power consumption threshold before operations begin. This threshold acts as a preventive measure, allowing the control unit to take corrective action before dangerous conditions develop, thus cushioning against potential damage to the drive and tool.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Adaptability or versatility

If manual adjustment of parameters is required during core drilling, then adaptability to changing conditions is improved, but user fatigue increases and operation becomes more difficult

Engineering Contradiction:

Improveparameter adjustmentVSAvoiduser fatigue

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The control system performs self-adjustment of drive speed based on automatic power consumption measurements. Instead of requiring the user to manually monitor and adjust parameters, the system autonomously regulates drive speed to maintain safe and efficient operation, thereby reducing user fatigue and simplifying operation.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The manual mechanical adjustment of parameters by the user is replaced with an automated electronic control system. The control unit electronically regulates drive speed based on measured power consumption, substituting the manual mechanical adjustment process with an automated electronic control mechanism.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3030368B1Intuitive, adaptive spot drilling function

Publication Date: 2023.08.02 HILTI AG

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AI summary

The invention relates to a method for controlling a machine tool (1), in particular a handheld core drill, containing a drive (10) for driving a tool (30) and a control unit (40), during the machining of a workpiece (W). The method contains the following steps: • - fixing the rotational drive speed at a first value; • - measuring a first current consumption value of the drive; • - fixing a threshold value for the current consumption of the drive; and • - increasing the rotational drive speed to a second value if the current consumption of the drive exceeds the threshold value due to an increase in the drive load. The invention further relates to a machine tool (1) for applying the method. The machine tool contains a drive (10) for driving a tool (30) and a control unit (40) for controlling at least the rotational drive speed.