Centrifugal Valve Phase Variation Mechanism for Engine Emissions

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Solution Overview

Problem

Current valve phase and lifting variation systems in internal combustion engines are bulky, costly, and difficult to maintain, and struggle to meet stringent pollution standards while achieving high performance and efficient emissions control across varying engine loads and speeds.

Innovation Solution

A compact, cost-effective automatic mechanical device for phase and lifting variation of valves using a centrifugal adjustment unit with helical grooved bush and conical cams, allowing for adjustable crossover angles and lifting positions through centrifugal force and spring preloading, enabling optimal engine performance and emission reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional valve phase and lifting variation systems are used, then engine performance and emissions control are improved, but the system becomes bulky, costly, and difficult to maintain

Engineering Contradiction:
ImproveemissionsVSAvoidsystem complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines phase variation and lifting variation functions into a single integrated mechanical device. The camshaft assembly integrates the cam profiles (for lifting) and the phase variation mechanism (with adjustable phasing) into one unified component, eliminating the need for separate systems and reducing overall complexity while maintaining emissions control capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces complex electronic control systems with a mechanically actuated phase variation mechanism. The adjustable phasing is achieved through mechanical means (camshaft positioning mechanism with adjustable timing) rather than electronic actuators and sensors, simplifying the system while maintaining performance

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Object-affected harmful factors

If phase variation is used to reduce crossover angle at low speeds, then emissions are reduced, but engine performance at high speeds may be compromised

Engineering Contradiction:
Improvehydrocarbon emissionsVSAvoidengine power
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements dynamic adjustability of the phase variation mechanism, allowing the crossover angle to be varied in real-time based on operating conditions. The camshaft phasing can be dynamically adjusted to optimize for emissions at low speeds or for performance at high speeds, resolving the trade-off between these conflicting requirements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the phasing parameter (crossover angle) based on operating conditions. By adjusting the camshaft timing position, the system can optimize the intake and exhaust valve timing to minimize hydrocarbon emissions at idle and low speeds, while maintaining adequate filling at high speeds when performance is prioritized

Inventive Principle:
Principle #35Parameter changes

3Productivity

If large crossover angle is used to improve cylinder filling at high revs, then engine torque increases, but emissions control and idle regularity deteriorate

Engineering Contradiction:
Improveengine torqueVSAvoidpolluting emissions
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent uses dynamic phasing adjustment to optimize the crossover angle based on engine operating conditions. At high speeds, the system can accommodate larger crossover angles for improved torque, while at low speeds it automatically reduces the crossover angle to maintain emissions control and idle regularity, eliminating the need for compromising fixed settings

Inventive Principle:
Principle #15Dynamics

4Object-affected harmful factors

If variable phasing system is implemented to meet pollution standards, then emissions are controlled, but system cost and manufacturing complexity increase

Engineering Contradiction:
Improvepolluting emissionsVSAvoidmanufacturing cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent integrates the phase variation and lifting variation functions into a single camshaft assembly, reducing the number of separate components that need to be manufactured and assembled. This integration lowers manufacturing complexity and cost while maintaining the capability to meet stringent emissions standards through optimized valve timing control

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

The solution provides a lightweight, efficient, and maintainable system that meets restrictive pollution standards, enhancing engine performance and reducing emissions across all operating conditions, from low loads to high performance scenarios.

Implementation Method 1

A compact, cost-effective automatic mechanical device for phase and lifting variation of valves using a centrifugal adjustment unit with helical grooved bush and conical cams, allowing for adjustable crossover angles and lifting positions through centrifugal force and spring preloading

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

A compact, cost-effective automatic mechanical device for phase and lifting variation of valves using a centrifugal adjustment unit with helical grooved bush and conical cams, allowing for adjustable crossover angles and lifting positions through centrifugal force and spring preloading

Methodology Applied
Scientific EffectSpring preloading: Spring

Data Source

PatentEP2161434B1Mechanical device for the phase and lifting variation of the valves in an internal combustion engine
Publication Date: 2011.12.14 PIAGGIO & C SPA
  • EP2161434B1 patent drawingFigure 1
  • EP2161434B1 patent drawingFigure 2~3
  • EP2161434B1 patent drawingFigure 4~4A

AI summary

The invention describes a device for the phase and lifting variation of the valves in an internal combustion engine (10) of the type comprising at least one valve control camshaft, made up of a first component (11; 34), operationally connected to at least a first cam (32), and of a second component (13; 30), operationally connected to at least a second cam (31). The first component (11; 34) and second component (13; 30) of the camshaft are connected to each other by means of a grooved bush (14; 42). The device comprises a centrifugal adjustment unit comprised of a container (19; 38) for one or more masses (20; 39) which radially slide on a counter wall (21; 40) integral with the first component (11; 34) of the camshaft. The movement of the masses (20; 39) causes the axial sliding, in the direction of the camshaft, of the container (19; 38) and the grooved bush (14; 42) thus making the displacement of the first component (11; 34) and/or the second component (13; 30) of the camshaft and, consequently, of the cams (31, 32) operationally connected to such components.