PCV Oil Return Passage Dipstick Integration

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Solution Overview

Problem

The existing methods for returning crankcase gases to the engine air intake to combust hydrocarbons face challenges due to the potential combustion of engine oil, which increases oil consumption and degrades exhaust gas after-treatment device performance, and require a motive force to overcome vacuum, often necessitating an excessive oil column that affects vehicle height and fuel economy.

Innovation Solution

Integrating the dipstick oil passage with the Positive Crankcase Ventilation (PCV) oil return passage to build oil head pressure, allowing efficient oil return to the crankcase sump even under high engine vacuum conditions, thereby overcoming the vacuum force and optimizing engine structure usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If vacuum is used to draw crankcase gases to engine cylinders, then crankcase gases are moved to engine cylinders for combustion, but vacuum also acts on separated engine oil making it more difficult to return oil to the crankcase

Engineering Contradiction:

Improvecrankcase gas flow rateVSAvoidoil return difficulty

Core Design Contradiction:

SpeedVSEase of operation

Solution Approach 1:

The system separates the gas flow path and oil return path into distinct channels. The PCV valve controls gas flow through one path while the oil return passage provides a separate path for oil, allowing independent control of gas ventilation and oil return to eliminate the adverse effect of vacuum on oil return

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A dedicated PCV oil return passage acts as an intermediary channel that facilitates oil return independently from the gas flow path. This intermediate structure allows oil to bypass the vacuum effect acting on the crankcase gases, enabling separate control of the two fluid streams

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stress or pressure

If an oil column is built to overcome vacuum and return oil to the crankcase, then oil head pressure is sufficient to overcome vacuum, but the oil column increases engine height and degrades vehicle fuel economy

Engineering Contradiction:

Improveoil head pressureVSAvoidvehicle fuel economy

Core Design Contradiction:

Stress or pressureVSWeight of moving object

Solution Approach 1:

The oil return passage is routed through the dipstick tube, utilizing the vertical dimension already present in the engine structure. By integrating the oil return path through the dipstick tube rather than creating a separate horizontal oil column, the system achieves necessary oil head pressure without increasing overall engine height or vehicle drag

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The dipstick tube serves dual functions: it provides access for oil level checking and simultaneously serves as the PCV oil return passage. This multi-functionality eliminates the need for a dedicated separate oil return structure that would increase engine height, as the dipstick tube already provides the necessary vertical pathway

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If a separate PCV oil return passage is created, then oil can be returned to the crankcase, but the passage competes with other engine elements for useful engine structure

Engineering Contradiction:

Improveoil return capabilityVSAvoidengine structure usage

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The PCV oil return passage is merged with the dipstick tube structure. The oil return passage utilizes the existing dipstick tube cavity and routing, combining the oil return function with the existing dipstick access structure. This integration eliminates the need for a separate dedicated oil return passage that would compete with other engine structural elements

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 enhances engine structure functionality, ensures continuous oil return to the sump, and maintains efficient oil head pressure to counteract engine vacuum, reducing oil consumption and preserving fuel economy.

Implementation Method 1

separate oil from engine crankcase gases

Methodology Applied

Scientific EffectGravitational settling: Sedimentation

Implementation Method 2

separate oil from crankcase gases that are directed from the engine crankcase to the engine air intake

Methodology Applied

Scientific EffectDensity difference: Density Gradient

Implementation Method 3

build oil head pressure. In other words, the weight of the column of oil can work against the vacuum and allow the separated oil to be returned to the engine crankcase

Methodology Applied

Scientific EffectHydrostatic pressure: Pressure Gradient

Implementation Method 4

Vacuum can draw crankcase gases to engine cylinders

Methodology Applied

Scientific EffectVacuum suction: Pressure Gradient

Data Source

PatentUS8347865B2System and method for returning oil separated from engine crankcase gases

Publication Date: 2013.01.08 FORD GLOBAL TECH LLC

AI summary

A system for processing PCV gases is disclosed. In one example, the system includes an oil passage solely linking an oil separator to an engine crankcase. The system can provide an oil column that provides for continuous oil return from the oil separator to the engine crankcase even during conditions of higher levels of engine vacuum.