Fastener Driver Guide Cylinder Ventilation

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Solution Overview

Problem

Existing setting tools for driving fasteners into substrates face inefficiencies due to dynamic pressure and energy loss issues, which affect the quality and efficiency of the fastening process.

Innovation Solution

The setting tool incorporates a guide cylinder with non-closable openings for ventilation, a squirrel-cage rotor, and an excitation coil, along with a capacitor for generating a magnetic field that accelerates the driving element, and a braking mechanism to manage kinetic energy, ensuring reduced pressure and energy loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the guide cylinder is sealed to maintain pressure during fastener driving, then driving force is improved, but energy loss increases due to dynamic pressure buildup and suction pressure behind the driving element

Engineering Contradiction:
Improvedriving forceVSAvoidenergy loss
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The guide cylinder incorporates non-closable openings (slits or holes) in its wall, creating a porous structure that allows controlled air flow. This resolves the contradiction by enabling pressure equalization between the front and rear cavities, reducing dynamic pressure buildup and suction pressure effects while maintaining sufficient driving force through the electromagnetic drive system.

Inventive Principle:
Principle #31Porous materials

2Loss of energy

If the guide cylinder has non-closable openings for ventilation, then energy loss is reduced, but structural integrity and sealing may be compromised

Engineering Contradiction:
Improveenergy lossVSAvoidstructural integrity
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The non-closable openings are strategically positioned only in specific regions of the guide cylinder wall, not uniformly distributed. This local modification maintains structural integrity in critical areas while providing ventilation where needed, resolving the contradiction between energy efficiency and structural strength.

Inventive Principle:
Principle #3Local quality

3Speed

If the driving element is accelerated using electromagnetic force from capacitor discharge, then driving speed is improved, but control precision becomes more difficult

Engineering Contradiction:
Improvedriving speedVSAvoidcontrol precision
Core Design Contradiction:
SpeedVSDifficulty of detecting and measuring

Solution Approach 1:

The system uses dynamic control of the electromagnetic drive, adjusting the discharge timing and parameters based on real-time feedback from sensors that detect the driving element's position and speed. This dynamic adjustment maintains high driving speed while improving control precision through active feedback control.

Inventive Principle:
Principle #15Dynamics

4Volume of moving object

If the guide cylinder volume is reduced to improve tool compactness, then portability is improved, but pressure management becomes more difficult

Engineering Contradiction:
Improvetool sizeVSAvoidpressure management
Core Design Contradiction:
Volume of moving objectVSStress or pressure

Solution Approach 1:

The guide cylinder is divided into two separate cavities (front and rear) by the piston plate, with non-closable openings providing controlled communication between them. This segmentation allows independent pressure management in each cavity while maintaining compact overall dimensions, resolving the contradiction between size and pressure control.

Inventive Principle:
Principle #1Segmentation

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

This configuration enhances the efficiency and quality of the fastening process by minimizing dynamic pressure and energy loss, allowing for effective and precise driving of fasteners into substrates.

Implementation Method 1

The drive has an electrical capacitor and a coil. To drive the driving element, the capacitor is discharged via the coil

Methodology Applied
Scientific EffectElectromagnetic field generation: Electromagnet

Implementation Method 2

the capacitor is discharged via the coil, as a result of which a Lorentz force acts on the driving element, so that the driving element is moved towards a nail

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Implementation Method 3

The openings ensure ventilation of the guide cylinder, as a result of which a dynamic pressure in front of the driving element and/or a suction pressure behind the driving element and an associated loss of energy are reduced

Methodology Applied
Scientific EffectAir flow through openings:

Data Source

PatentEP3801998B1Fastener driver
Publication Date: 2023.03.29 HILTI AG
  • EP3801998B1 patent drawingFigure 1
  • EP3801998B1 patent drawingFigure 2~3
  • EP3801998B1 patent drawingFigure 4~5

AI summary

The invention relates to a fastener driving tool for driving fastening elements into a substrate, said fastener driving tool comprising: a receptacle which is provided to receive a fastening element; a driving element which is provided to convey a fastening element received in the receptacle along a setting axis into the substrate, said driving element having a piston plate and a piston rod; a drive which is provided to drive the driving element along the setting axis towards the fastening element; a guide cylinder in which the piston plate is guided along the setting axis; and passages through which air escapes from the cylinder.