Intake Air Temperature Sensor Heat Interference Reduction

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Solution Overview

Problem

In internal combustion engine physical quantity detection devices, the heat transfer from other components on the same substrate affects the measurement accuracy of temperature detection elements, leading to reduced precision due to circuit self-heating and increased complexity in assembly.

Innovation Solution

The physical quantity detection device optimizes the arrangement of components on the electronic circuit board, reducing heat transfer from other components and improving measurement accuracy by integrating the circuit board within the housing and using a resin molding process to fix the detection units, thereby minimizing the impact of heat and fluid resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the temperature measuring element and driving circuit are not directly connected, then the measurement accuracy is improved by reducing heat transfer, but the device complexity increases due to additional lead terminals and assembly steps

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidassembly complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The temperature measuring element is extracted from the circuit board substrate and positioned in a separate location within the housing. This physical separation removes the heat source (circuit board) from the measurement location, eliminating thermal interference while maintaining electrical connection through conductive paths in the housing structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The housing structure serves as an intermediary medium that provides both mechanical support and electrical connection between the temperature measuring element and the driving circuit. The conductive paths through the housing allow signal transmission while the physical separation prevents heat transfer from affecting measurements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If electronic components are densely mounted on the circuit board, then the productivity is improved, but the measurement precision deteriorates due to increased circuit self-heating

Engineering Contradiction:
Improvecomponent mounting densityVSAvoidtemperature detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The temperature measuring element is extracted from the circuit board and positioned in the housing, separating it from the heat-generating electronic components. This allows high-density component mounting on the circuit board without compromising measurement accuracy, as the sensor is physically isolated from thermal interference.

Inventive Principle:
Principle #2Taking out (Extraction)

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 measurement accuracy of intake air physical quantities while reducing assembly complexity and heat influence, leading to improved reliability and precision in engine control systems.

Implementation Method 1

a temperature sensor that directly comes into contact with the air flow and detects the intake air temperature

Methodology Applied
Scientific EffectThermal energy detection: Thermal Radiation

Implementation Method 2

blocking a heat transfer path from other components mounted on the circuit board to the temperature sensor

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3358316B1Physical quantity detection device
Publication Date: 2023.05.10 ASTEMO LTD
  • EP3358316B1 patent drawingFigure 1
  • EP3358316B1 patent drawingFigure 2-1
  • EP3358316B1 patent drawingFigure 2-2

AI summary

The present invention reduces, by optimizing disposition of components on an electronic circuit board, heat transfer from other components mounted on the same board, and improves measurement accuracy of an intake air temperature detection element. A physical quantity detection device 300 of the present invention has an electronic circuit board 400, which is provided with one or more intake air temperature detection elements 422, 453 (elements having intake air temperature detection function), and which processes electric signals. Furthermore, the physical quantity detection device has a configuration wherein the intake air temperature detection elements 422, 453, and a power supply regulator 41 having the maximum heat generation quantity are mounted on the same electronic circuit board 400. The physical quantity detection device is characterized in that the intake air temperature detection elements 422, 453 are disposed on the air flow upstream side of the power supply regulator 41.