Automotive Door Sensor Hollow Part Coating

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Solution Overview

Problem

Protectors with sensors installed on automobiles are prone to damage and malfunction due to the thin, weak parts of the hollow structure cracking when convex objects, such as automobile keys, come into contact with them, leading to issues with sensor functionality and water ingress.

Innovation Solution

A coating layer with a Shore D hardness of 7-47 is applied to the outer peripheral surface of the hollow part, covering the inner-cabin and outer-cabin side ends, to enhance the strength and durability of the thin parts while maintaining sensor functionality, and the conductive parts are shaped to create a V-shaped space for wider detection ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the hollow part is made with thin walls to maintain flexibility for sensor detection, then the sensor can detect objects effectively, but the thin parts are weak and prone to cracking when convex objects abut them

Engineering Contradiction:
Improvesensor detection capabilityVSAvoidstrength of hollow part
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent applies a coating layer specifically to the thin parts of the hollow part's outer peripheral surface, creating local reinforcement only where needed. This allows the thin-walled structure to maintain its flexibility for sensor detection while the coated areas gain enhanced strength and crack resistance against convex objects like automobile keys.

Inventive Principle:
Principle #3Local quality

2Reliability

If the hollow part is made with thin walls to maintain flexibility, then the sensor function is preserved, but water can ingress through cracks causing malfunction

Engineering Contradiction:
Improvesensor functionVSAvoidwater ingress
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The coating layer is applied in advance to the thin parts of the hollow part before any potential water ingress can occur. This preventive measure creates a protective barrier that cushions against future cracking and water penetration, ensuring the sensor function remains reliable over time.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent uses a coating layer as a thin film structure on the hollow part's outer surface. This thin film provides protective functionality against water ingress and mechanical damage while maintaining the underlying flexible, thin-walled structure necessary for sensor operation.

Inventive Principle:
Principle #30Flexible shells and thin films

3Strength

If a hard coating is applied to strengthen the hollow part, then the strength increases, but the sensor detection sensitivity may be reduced

Engineering Contradiction:
Improvestrength of hollow partVSAvoidsensor detection sensitivity
Core Design Contradiction:
StrengthVSMeasurement precision

Solution Approach 1:

The coating layer is applied selectively only to the thin parts of the hollow part's outer peripheral surface, not the entire surface. This localized approach strengthens vulnerable areas while leaving other areas uncovered, preserving the overall flexibility and detection sensitivity of the sensor.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent specifies that the coating layer's Shore D hardness should be 7-47, optimizing the balance between providing sufficient strength protection and maintaining adequate flexibility for sensor operation. This parameter control ensures the coating protects against cracking while not being so hard as to interfere with detection sensitivity.

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 coating layer effectively prevents damage and cracking of the hollow part, maintains sensor functionality by preventing water ingress, and ensures proper operation of the sliding door and sun roof mechanisms.

Implementation Method 1

A coating layer with a Shore D hardness of 7-47 is applied to the outer peripheral surface of the hollow part

Methodology Applied
Scientific EffectHardness: Shore Durometer

Implementation Method 2

a sensor (pressure sensitive sensor) 80 which outputs a corresponding electric signal upon detecting the object

Methodology Applied
Scientific EffectPressure sensitive detection: Piezoresistive Effect

Data Source

PatentEP3023280B1Protector with sensor
Publication Date: 2020.06.24 NISHIKAWA RUBBER CO LTD
  • EP3023280B1 patent drawingFigure 1
  • EP3023280B1 patent drawingFigure 2
  • EP3023280B1 patent drawingFigure 3(a)~3(b)

AI summary

A protector with a sensor operatively coupled on a sliding door detects an object by touch between two conductive parts in a hollow part with a space therebetween. The two conductive parts including a conductive part on a lower part of the hollow part as a side of the installation base member and a conductive part on an upper part of the hollow part as a side of a top end are shaped and positioned in a manner that an inner-cabin side end and an outer-cabin side end of the space are continuously provided directly on an inner peripheral surface of the hollow part. A coating layer covers at least an outer peripheral surface of the outer coat of the hollow part having the inner-cabin side end and the outer-cabin side end of the space continuously provided directly on the inner peripheral surface thereof.