Indirect Fuel Temperature Sensing in Combustion Setting Tools

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Solution Overview

Problem

Existing combustion-powered setting tools face challenges in precisely measuring the temperature of fuel in storage containers for optimal fuel addition to the combustion chamber, requiring complex temperature sensing mechanisms.

Innovation Solution

A setting tool design featuring a temperature sensor in mechanical contact with the outer surface of a metal storage container wall, utilizing an elastic element for consistent contact and potentially a thermally conductive paste for improved heat transfer, allows indirect and precise temperature detection of fuel inside the container.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a temperature sensor is placed inside the storage container to directly measure fuel temperature, then measurement precision is improved, but device complexity and risk of fuel contamination increase

Engineering Contradiction:
Improvefuel temperature measurementVSAvoidtemperature sensing mechanism
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses the storage container wall as an intermediary medium to transfer thermal information from the fuel to the temperature sensor. The sensor measures the temperature of the container wall, which indirectly reflects the fuel temperature, avoiding direct contact between the sensor and fuel while maintaining measurement accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces a complex direct-contact temperature sensing system with a simpler indirect measurement system. By utilizing the thermal conductivity of the container wall, the system substitutes mechanical/direct thermal contact with thermal conduction through the wall material, simplifying the overall sensing mechanism.

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

2Measurement precision

If the storage container wall is made of metal with good thermal conductivity, then temperature detection accuracy is improved, but the container may be more prone to corrosion or chemical reactions with fuel

Engineering Contradiction:
Improveouter surface temperature detectionVSAvoidcontainer durability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent employs a composite wall structure consisting of an inner plastic layer for chemical resistance and an outer metal layer for thermal conductivity. This composite material approach combines the advantages of both materials: the plastic provides protection against fuel corrosion while the metal enables effective heat transfer to the temperature sensor.

Inventive Principle:
Principle #40Composite materials

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 accurate and effortless temperature monitoring of fuel, ensuring precise fuel addition to the combustion chamber, enhancing the tool's operational efficiency with minimal technical complexity and cost.

Implementation Method 1

the temperature sensor for detecting the temperature of the fuel in the storage container is in mechanical contact with an outer surface of the container wall for indirect detection of the fuel temperature

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the temperature sensor is pressed against the outer surface of the container wall, in particular an end wall or a bottom wall, of the storage container by a force applied to the temperature sensor by the elastic element

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

A generally gaseous fuel is introduced into the combustion chamber, creating a mixture of air and fuel. For optimal combustion, the ratio of fuel to oxygen within the combustion chamber must be precisely balanced.

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

The temperature of the combustion chamber and the temperature of the fuel are transmitted to a management module, which controls the opening time of a metering device

Methodology Applied
Scientific EffectPressure increase: Pressure Increase

Data Source

PatentEP3074185B1Setting device with temperature sensor
Publication Date: 2020.11.18 HILTI AG
  • EP3074185B1 patent drawingFigure 1
  • EP3074185B1 patent drawingFigure 2
  • EP3074185B1 patent drawingFigure 3

AI summary

The invention relates to a setting device (1), comprising a housing (3), a combustion chamber (4) having an ignition apparatus (5), preferably a storage container (7) having a container wall (9) for storing fuel, a dosing apparatus (14) for adding a specified volume of fuel to the combustion chamber (4), an apparatus (17), such as a firing pin (18), for inserting a setting element (19) into a setting object (2), and a setting force can be applied to the apparatus (17) as a result of the pressure of gas in the combustion chamber (4) such that the apparatus (17) is operable by combustion force, a control unit (25), a temperature sensor (26) for detecting the temperature of the fuel in the storage container (7), wherein the problem to be solved by the invention is the detecting of the temperature of the fuel in the storage container (7) by means of little technical effort, for precise addition of a specified volume of fuel to the combustion chamber (4). This problem is solved in that the setting device (1) is designed such that, in the case of a storage container (7) connected to the setting device (1), the temperature sensor (26) for detecting the temperature of the fuel in the storage container (7) mechanically contacts an outer surface (13) of the container wall (9), for indirect detection of the temperature of the fuel.