EMC Circuit in Intake Manifold Sensor Housing

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Solution Overview

Problem

Existing devices for recording pressure and temperature in an intake manifold of an internal combustion engine suffer from signal interference due to electromagnetic compatibility issues, particularly in the wiring connection between the temperature sensor and the evaluation circuit, leading to inaccurate temperature measurements.

Innovation Solution

Integration of an EMC protective circuit within the housing or directly connected to the temperature sensor, which is designed to minimize interference by using an interference-suppression capacitor, often in the form of an SMD capacitor, to ensure signal integrity by keeping signal paths short and independent of external wiring configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a passive temperature sensor is connected via a wiring harness to an external evaluation circuit, then the device structure remains simple, but electromagnetic interference affects the signal accuracy

Engineering Contradiction:

Improvedevice structureVSAvoidtemperature measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

An EMC protective circuit is introduced as an intermediary component between the temperature sensor and the external evaluation circuit. This protective circuit filters electromagnetic interference from the sensor signal before it reaches the evaluation circuit, thereby maintaining signal accuracy without requiring a completely redesigned system architecture.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The device is segmented into distinct functional zones: a sensor housing containing the temperature sensor and EMC protective circuit, and an external evaluation circuit. This segmentation isolates the sensitive sensing function from potential interference sources while maintaining structural simplicity through modular design.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If the evaluation circuit is integrated into the common housing with the sensors, then signal processing is simplified, but the housing becomes more complex and expensive

Engineering Contradiction:

Improvehousing structureVSAvoidproduction simplicity

Core Design Contradiction:

Device complexityVSEase of manufacture

Solution Approach 1:

The system is divided into a sensor housing module containing only the temperature sensor and EMC protective circuit, and a separate evaluation circuit. This segmentation keeps the housing structure simple and inexpensive while maintaining ease of manufacture, as each module can be produced independently and assembled.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The evaluation circuit is extracted from the common housing and placed externally. This extraction removes the complexity and cost associated with integrating full signal processing capabilities into the housing, while the essential signal protection function remains within the housing via the EMC protective circuit.

Inventive Principle:

Principle #2Taking out (Extraction)

3Adaptability or versatility

If the temperature sensor signal is evaluated externally without EMC protection, then the wiring configuration remains flexible, but electromagnetic interference degrades signal quality

Engineering Contradiction:

Improvewiring configuration flexibilityVSAvoidsignal integrity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The EMC protective circuit serves as an intermediary that filters electromagnetic interference from the temperature sensor signal. This allows the signal to be evaluated externally with flexible wiring configurations while ensuring signal integrity through the protective filtering function.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Electromagnetic interference filtering is performed preliminarily within the sensor housing before the signal leaves the housing. This preliminary action ensures that the signal reaching the external evaluation circuit is already protected, allowing flexible wiring configurations without compromising signal quality.

Inventive Principle:

Principle #10Preliminary action

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 effectively suppresses electromagnetic interference, ensuring accurate temperature and pressure readings by isolating the signal evaluation outside the housing, thereby preventing noise from affecting the sensor signals and maintaining precise measurements.

Implementation Method 1

An EMC protective circuit 4 which is integrated into the housing 2 and/or is situated on the housing is electrically connected to the temperature sensor 3. The EMC protective circuit 4 is formed of an interference-suppression capacitor.

Methodology Applied

Scientific EffectElectromagnetic interference suppression: Capacitance

Data Source

PatentUS8192078B2Device for recording the pressure and the temperature in an intake manifold of an internal combustion engine

Publication Date: 2012.06.05 ROBERT BOSCH GMBH

AI summary

A device for recording the pressure and the temperature in an intake manifold of an internal combustion engine, a pressure sensor and a temperature sensor being situated in a common housing, and an evaluation of a signal of the temperature sensor being provided outside the housing. An EMC protective circuit is provided in this context, which is integrated into the housing and/or is situated on the housing, and is electrically connected to the temperature sensor.