Sensor Protector Sealing via Dual Injection Molding

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Solution Overview

Problem

Existing methods for molding end parts of protectors with sensors on automobiles result in uneven product shapes and inadequate sealing, requiring additional processes and materials that increase complexity and cost.

Innovation Solution

The use of an extrusion molded part made of a rubber-like elastic body with a hollow part containing core wires and a space, where the core wires are connected to leads and sealed with a primary and secondary sealing layer formed through injection molding, preventing water ingress and ensuring stable sealing without extra adhesive or supporting members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adhesive is used to seal wire connection parts, then sealing function is improved, but manufacturing complexity and time are increased

Engineering Contradiction:

Improvesealing functionVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the chemical bonding system (adhesive) with a mechanical sealing system (rubber-like elastic body). The extrusion molded part made of rubber-like elastic body provides sealing through its material properties and deformation capability, eliminating the need for adhesive application and curing processes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state and properties of the sealing material from rigid adhesive to flexible rubber-like elastic body. This parameter change allows the sealing material to deform and conform to the wire connection parts, providing effective sealing through elastic deformation rather than chemical bonding.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If adhesive is used to seal wire connection parts, then sealing function is improved, but operational time is increased

Engineering Contradiction:

Improvesealing functionVSAvoidoperational time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the time-consuming adhesive application and curing process with an immediate mechanical sealing system. The rubber-like elastic body provides sealing function upon installation without requiring additional time for application or curing, significantly reducing operational time.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If die molding is performed without preventing material flow, then manufacturing simplicity is improved, but sensor malfunction occurs

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidsensor function

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces the rubber-like elastic body as an intermediary material between the die molding process and the sensor components. This intermediary material prevents die molding material from flowing into and damaging the sensor, while allowing the molding process to proceed without complex additional measures.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If additional parts and adhesives are used for sealing, then sealing reliability is improved, but device complexity is increased

Engineering Contradiction:

Improvesealing reliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the sealing function with the existing extrusion molded part by making it from rubber-like elastic body. This consolidation eliminates the need for separate sealing parts and adhesives, reducing device complexity while maintaining sealing reliability through the inherent properties of the elastic material.

Inventive Principle:

Principle #5Merging (Combining)

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 approach stabilizes the sealing function, reduces operational time, and ensures uniform product shapes by eliminating the need for additional parts and adhesives, while preventing sensor malfunction due to die molding material flow.

Implementation Method 1

the rubber like elastic bodies 34, 35 contact with each other and the two core wires 31, 32 short

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

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

Methodology Applied

Scientific EffectPiezoresistive Effect: Piezoresistive Effect

Implementation Method 3

a primary sealing layer 100 and a secondary sealing layer 200 formed thereon by means of injection molding

Methodology Applied

Scientific EffectInjection Molding:

Data Source

PatentUS9605473B2Protector with sensor and method of molding end part of the same

Publication Date: 2017.03.28 NISHIKAWA RUBBER CO LTD

AI summary

A protector with a sensor is installed on a sliding door for detecting an object by touch between two core wires in a hollow part. In a terminal part of the protector with the sensor, the core wires drawn out are connected with leads joined with a control unit. A primary seal is formed by means of injection molding for covering wire connection parts and another end side of an insert while also covering a skin of a wire harness which ties and coats the two leads. A secondary seal is formed by means of the injection molding for coating a part formed with the primary seal and for forming an external shape of a product.