Engine Temperature Sensor Terminal Flange Sealing and Fast Assembly

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Solution Overview

Problem

Existing temperature sensors for vehicle engines, particularly thermocouple sensors, face issues with insufficient sealing and complex manufacturing processes, leading to assembly challenges and high production time.

Innovation Solution

A temperature sensor design featuring a housing with a flange for holding terminals, where the flange is fixed via plastic deformation of a holding pin, and a connector with a metal insert for electrical connection, along with a fiber-loaded material for enhanced mechanical strength and sealing, and a method of manufacturing where lugs are folded inside the housing using a folding tool.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the housing uses conventional sealing methods with ribs remelted during plastic injection, then the sealing structure is simple, but the sealing quality is insufficient due to imperfect fusion

Engineering Contradiction:
Improvesealing qualityVSAvoidsealing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the sealing mechanism from thermal fusion of ribs to mechanical deformation of a metal flange. The flange is crimped onto the housing and deformed to engage with grooves, providing reliable sealing through mechanical interlocking rather than imperfect plastic fusion. This parameter change from thermal to mechanical sealing resolves the contradiction between sealing quality and structural simplicity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a composite sealing structure combining metal flange with plastic housing. The metal flange provides superior sealing and mechanical strength, while the plastic housing maintains simplicity. This composite approach achieves high reliability sealing without requiring complex modified sealing structures in the housing itself.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the sensor assembly uses multiple components including terminals brazed to PCB with crimped connections, then the electrical connection is robust, but the manufacturing complexity increases and assembly time increases

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidassembly speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent merges the terminal connection functions into an integrated flange structure that simultaneously provides mechanical retention and electrical connection. The flange is crimped onto the wire conductor and also engages with the housing grooves, combining multiple functions into a single component and operation, thereby reducing assembly steps while maintaining connection reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The flange structure is designed to be self-retaining through its deformation characteristics. When crimped, the flange automatically engages with the housing grooves and secures the terminal without requiring additional fastening operations or complex assembly steps. This self-service mechanism reduces assembly time while ensuring reliable electrical and mechanical connections.

Inventive Principle:
Principle #25Self-service

3Strength

If the flange holding pin has small diameter, then the housing structure remains simple, but the mechanical strength and retention force are insufficient

Engineering Contradiction:
Improveflange retention strengthVSAvoidholding pin structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent changes the holding pin diameter parameter to be greater than or equal to 1.5mm, which significantly increases the mechanical strength and retention capability of the flange connection. This parameter change ensures that the flange can withstand the forces applied during crimping and operation without deformation or failure, resolving the contradiction between strength and structural simplicity.

Inventive Principle:
Principle #35Parameter changes

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

The solution provides improved sealing and reduced complexity in assembly, resulting in a more robust and precise temperature sensor with enhanced mechanical strength and reduced assembly time.

Implementation Method 1

the flange being fixed to the housing via the plastic deformation of at least one holding pin arranged in the housing

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

The thermocouple measurement principle is based on the Seebeck effect which results in a potential difference between two different metal wires when they are subjected to a temperature difference

Methodology Applied
Scientific EffectSeebeck effect: Seebeck Effect

Implementation Method 3

the terminal consisting of a portion crimped on a conductor placed in the box

Methodology Applied
Scientific EffectCrimping: Deformation

Data Source

PatentEP3949026B1Temperature sensor for vehicle engine and manufacturing method thereof
Publication Date: 2023.11.08 SC2N SA
  • EP3949026B1 patent drawingFigure 1~2
  • EP3949026B1 patent drawingFigure 3~4
  • EP3949026B1 patent drawingFigure 5~7

AI summary

The present invention relates to a temperature sensor (1) for a motor vehicle, comprising: - a casing (1) containing circuit board (14) and traversed by at least one pair (2) of wires (3) provided with terminals (8), the terminal (8) being made up of a portion (804) crimped onto a conductor (5) arranged in the casing (1), - a connector (101) comprising at least one metal insert (10) providing an electrical connection with the circuit board (14) characterized in that the casing comprises at least one flange (9) for holding the terminals (8), the terminals (8) being folded.