Intake Manifold PCV Chamber Design for Blowby Gas Distribution

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Solution Overview

Problem

Existing intake manifolds for engines face issues with uneven distribution of blowby gas to branch pipes and the risk of water from blowby gas freezing the throttle valve, especially in cold conditions, due to the placement of the PCV chamber relative to the surge tank and throttle valve.

Innovation Solution

The intake manifold design includes a PCV chamber positioned upstream of the central part of the surge tank, with a blowby gas introduction port and an exhaust port located higher than the introduction port, and a drain hole positioned downstream of the exhaust port, along with protruding parts on the surge tank's bottom wall to create opposing swirling currents, ensuring even blowby gas distribution and preventing water from reaching the throttle valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the PCV chamber is provided on the downstream side of the surge tank, then the structure is simpler, but blowby gas is not evenly distributed to the branch pipes

Engineering Contradiction:

ImprovePCV chamber positionVSAvoidblowby gas distribution uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The PCV chamber is divided into multiple discharge ports (first and second blowby gas exhaust ports) positioned at different locations to serve different branches of the branch pipes, ensuring even distribution of blowby gas to all cylinders

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If the PCV chamber is provided upstream of the central part of the surge tank, then blowby gas is evenly distributed to the branch pipes, but water discharged into the surge tank may flow backward to the throttle valve side and cause freezing

Engineering Contradiction:

Improveblowby gas distribution uniformityVSAvoidwater freezing throttle valve

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The water discharge function is extracted from the main PCV chamber and directed through a separate drain hole to a water discharge port positioned at the downstream end of the surge tank, separating the water discharge path from the blowby gas path to prevent water from reaching the throttle valve

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The downstream end of the surge tank serves as an intermediary location where water is discharged separately from the main blowby gas flow, acting as a buffer zone that prevents water from flowing backward to the throttle valve while still allowing blowby gas to be evenly distributed

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If the blowby gas exhaust port is located at a higher position than the blowby gas introduction port, then water is prevented from being dragged into the surge tank, but the PCV chamber requires more vertical space

Engineering Contradiction:

Improvewater scattering into surge tankVSAvoidPCV chamber vertical space

Core Design Contradiction:

Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The PCV chamber is positioned upstream of the central part of the surge tank in the longitudinal direction, utilizing the longitudinal dimension of the surge tank rather than requiring additional vertical space, thereby maintaining compact design while achieving even blowby gas distribution

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 configuration ensures even distribution of blowby gas to branch pipes and prevents water from reaching the throttle valve, thereby maintaining smooth engine operation and preventing freezing issues in cold conditions.

Implementation Method 1

the blowby gas exhaust port is located at a position higher than the blowby gas introduction port... it is possible to prevent water inside the PCV chamber from being dragged by the blowby gas

Methodology Applied

Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

the bottom wall of the surge tank includes at least one protruding part that protrudes upward... create opposing swirling currents, ensuring even blowby gas distribution

Methodology Applied

Scientific EffectVortex flow: Vortex Ring

Implementation Method 3

a drain hole that is designed to discharge water, contained in the blowby gas, from the PCV chamber into the surge tank

Methodology Applied

Scientific EffectGravity: Gravitation

Data Source

PatentUS10890088B2Intake manifold for engine

Publication Date: 2021.01.12 HONDA MOTOR CO LTD

AI summary

An intake manifold 10 includes: a surge tank 11 that is connected on an upstream side thereof to a throttle valve 13; multiple branch pipes 12 that are arranged side by side in a longitudinal direction of the surge tank 11 and respectively connected to cylinders; and a PCV chamber 15 that is provided upstream of a central part in the longitudinal direction of the surge tank 11. The intake manifold includes: a blowby gas introduction port 16g that is designed to introduce blowby gas into the PCV chamber 15; and a blowby gas exhaust port 16f that is designed to discharge the blowby gas from the PCV chamber 15 into the surge tank 11, and the blowby gas exhaust port 16f is located at a position higher than the blowby gas introduction port 16g.