Engine Cylinder Effective Compression Ratio Control via Valve Timing

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Solution Overview

Problem

Engines optimized for a single fuel type struggle to achieve optimal performance, fuel economy, and emissions when operating on fuel blends, such as ethanol and gasoline, due to differences in properties like volatility, heating value, and octane number.

Innovation Solution

A method and system that adjust the effective compression ratio in an engine cylinder by using a database of volume compression ratios for various fuels, with a fuel sensor detecting fuel composition and adjusting intake and/or exhaust valve timing to achieve an optimal compression ratio based on the identified fuel, allowing for a range of 5:1 to 20:1 volume compression ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an engine is calibrated for a specific fuel type to optimize performance, then fuel economy and emissions are improved for that fuel, but the engine cannot achieve optimal performance when operated on fuel blends with different properties

Engineering Contradiction:

Improvefuel compatibilityVSAvoidperformance optimization

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The engine control system dynamically adjusts valve timing parameters based on detected fuel composition. The system transitions from a static, fuel-specific calibration to a dynamic, adaptive control mode that modifies intake and exhaust valve timing in real-time to match the detected fuel blend, thereby maintaining optimal performance across varying fuel types

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (valve timing) in response to changes in fuel properties. When fuel composition is detected to differ from the base calibration fuel, the control system modifies timing parameters to compensate for differences in volatility, heating value, and octane number, restoring optimal combustion conditions

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If valve timing is adjusted to change the effective compression ratio, then the engine can adapt to different fuel compositions, but the system complexity increases

Engineering Contradiction:

Improvefuel blend adaptationVSAvoidcontrol system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The existing valve timing control mechanism, originally designed for a single fuel type, is made multi-functional by enabling it to handle multiple fuel compositions. The same hardware components (valves, actuators, control unit) perform the additional function of adapting to fuel blends through software-based timing adjustments, avoiding the need for separate hardware systems

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system replaces complex mechanical adjustments with electronic control. Instead of requiring physical modifications to the engine architecture to handle different fuels, the invention uses electronic sensor detection and electronic timing control to achieve fuel adaptability, substituting mechanical complexity with electronic intelligence

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS8857381B2Process and system for controlling effective compression ratios in an engine cylinder

Publication Date: 2014.10.14 SOUTHWEST RES INST

AI summary

The present disclosure is directed at the control of an effective compression ratio setting in an engine which may use a variety of fuels or fuel blends. The effective compression ratio may be selected based upon information from a fuel sensor and stored information regarding the detected fuel composition. The effective compression ratio may be adjusted for a selected cylinder by intake or exhaust valve timing.