Combustion Setting Tool Pre-Chamber Venting for Faster Piston Drive
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Combustion-powered setting tools face inefficiencies in venting the antechamber, leading to energy loss and potential backpressure issues due to residual gases, which hinder the rapid movement of the driving piston and overall effectiveness in driving fasteners into substrates.
Innovation Solution
The implementation of two axial ventilation connections with through-openings in the antechamber, which are closed and opened by a control sleeve to facilitate rapid venting, combined with a non-return valve device to manage excess pressure and prevent backflow, allowing for effective expulsion of gases and fresh air intake.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a single ventilation connection is used in the antechamber, then the structure is simple, but the venting speed is insufficient and backpressure remains high
Solution Approach 1:
The single ventilation connection is segmented into multiple ventilation connections (first and second) spaced apart axially in the antechamber. This segmentation allows gases to escape through multiple pathways simultaneously, significantly increasing the venting speed and reducing backpressure during piston movement.
Solution Approach 2:
The ventilation connections are arranged in different axial positions within the antechamber, utilizing the axial dimension to create multiple escape routes for gases. This spatial distribution maximizes the venting effectiveness without proportionally increasing structural complexity.
2Productivity
If the antechamber is not rapidly vented, then the structure remains sealed, but energy is lost and backpressure hinders piston movement
Solution Approach 1:
The ventilation connections are pre-positioned and designed to open at specific moments during piston movement. The control sleeve is configured to open these connections at the optimal time before the piston reaches positions where backpressure would significantly hinder movement, thereby maintaining productivity and minimizing energy loss.
Solution Approach 2:
The rapid venting mechanism allows the system to quickly escape residual gases during critical phases of piston movement, effectively 'skipping' through the problematic backpressure period. This minimizes the duration of energy loss and maintains high piston movement efficiency.
3Ease of operation
If ventilation connections are opened too early, then backpressure is reduced, but fresh air intake may be compromised
Solution Approach 1:
The control sleeve mechanism provides feedback-based control of the ventilation connections. It responds to pressure conditions and piston position, opening or closing connections at the appropriate moments. This feedback control ensures that ventilation occurs at optimal times, maintaining both ease of operation and reliable pressure control.
Solution Approach 2:
The ventilation connections are designed to be dynamically controllable rather than fixed. The control sleeve enables the system to adapt the opening and closing of ventilation connections based on real-time operating conditions, optimizing both gas management and pressure control throughout the operational cycle.
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 solution enables rapid reduction of backpressure in the antechamber, preventing energy loss and ensuring the driving piston moves efficiently, thereby enhancing the tool's effectiveness and energy efficiency by avoiding exhaust gas cushions during operation.
Implementation Method 1
at least one main combustion chamber for a fuel, with a driving piston that can be driven in a setting direction via expandable gases from the main combustion chamber
Implementation Method 2
an antechamber that is assigned an ignition device and in which a pressure acting on the main combustion chamber can be built up before the ignition of a fuel-air mixture in the main combustion chamber
Implementation Method 3
a driving piston that can be driven in a setting direction via expandable gases from the main combustion chamber
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a fuel-operated firing device (1) for driving securing elements into a substrate, comprising at least one main combustion chamber (6) for a fuel, a driving piston (10) that can be driven out of the main combustion chamber (6) in a firing direction (15) by means of expandable gases, and a pre-chamber (25) with which an ignition device (26) is associated and in which a pressure acting on the main combustion chamber (6) can build up prior to a fuel-air mixture being ignited in said main combustion chamber (6). In order to improve the efficacy and/or functionality during the driving in of securing elements using the fuel-operated firing device (1), the pre-chamber (25) has at least two venting connections (108; 109) which are mutually spaced in an axial direction and which have passages (31, 32;111, 112) that can be exposed conjointly in order to facilitate rapid venting of the pre-chamber (25).