Washer Nozzle Water Repellent Flow Path

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Solution Overview

Problem

Washer nozzles with heaters require additional components and wiring, increasing costs, and their performance can be compromised by airflow, leading to inconsistent washing liquid placement on windshields.

Innovation Solution

A washer nozzle design featuring a water-repellent material for the inner peripheral surface of the flow path to prevent liquid ingress and freezing, combined with a flow rectifying portion on the wiper arm to manage airflow and ensure accurate liquid placement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a heater is provided at the washer nozzle to prevent freezing, then the washing liquid can be jetted out in cold regions, but the cost increases due to additional lead wires and heater components

Engineering Contradiction:

Improvenozzle performance in cold regionsVSAvoidheater structure and wiring

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the thermal field solution (heater) with a mechanical/chemical field solution (water repellent coating). The water repellent portion is formed by applying a repellent substance to the inner peripheral surface of the flow path, creating a hydrophobic barrier that prevents water adhesion and freezing without requiring any heating mechanism or electrical wiring.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The water repellent coating is a simple, low-cost material application that can be easily reapplied if needed. Instead of investing in expensive heater assemblies with lead wires and electrical components, the patent uses an inexpensive coating material that provides the same anti-freezing function through surface chemistry rather than thermal energy.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Productivity

If the washer nozzle projects outward from the wiper arm, then the washing liquid can be supplied efficiently onto the windshield, but airflow from the base end toward the distal end affects the jetted liquid and may cause it to miss the predetermined position

Engineering Contradiction:

Improvewashing liquid supply efficiencyVSAvoidliquid placement accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by positioning the water repellent portion at the jetting hole and flow path outlet area before the liquid is jetted. This pre-established hydrophobic barrier immediately repels the washing liquid as it exits, counteracting the disruptive airflow effects before they can significantly deflect the liquid stream from its intended trajectory.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent changes the surface property parameter of the flow path inner peripheral surface by applying a water repellent coating. This modifies the contact angle and adhesion characteristics between the washing liquid and the nozzle surface, causing the liquid to bead up and exit more cleanly without being held back by surface tension or disrupted by airflow in the same way wet surfaces would be.

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 maintains nozzle performance across varying environments without the need for heaters, reducing costs and ensuring consistent washing liquid delivery on windshields by preventing liquid freezing and managing airflow effects.

Implementation Method 1

a water repellent portion that, at at least a portion of the flow path, structures an inner peripheral surface that extends to the jetting hole, and the water repellent portion is formed of a material that is water repellent

Methodology Applied

Scientific EffectWater repellency: Hydrophobe

Data Source

PatentUS10442407B2Washer nozzle, wiper arm equipped with nozzle, and vehicle wiper device

Publication Date: 2019.10.15 DENSO CORP

AI summary

A washer nozzle comprises: a nozzle connecting portion to which a hose, that supplies a washing liquid, is connected; a nozzle main body portion that has, at an interior thereof, a flow path that communicates with an interior of the nozzle connecting portion and that has a jetting hole that opens toward an exterior at one end side of the nozzle main body portion, the nozzle main body portion jetting the washing liquid out toward a windshield glass of a vehicle from the jetting hole; and a water repellent portion that, at at least a portion of the flow path, structures an inner peripheral surface that extends to the jetting hole, and that is formed of a material that is water repellent.