Active Tappet Torque Modulation for Internal Combustion Engine
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Solution Overview
Problem
Existing methods for modulating engine output torque are either slow or inefficient, leading to delayed responses and increased waste heat and emissions, particularly when using throttle valve control or varying ignition timing.
Innovation Solution
The method involves using an active tappet to control the air charge in the combustion chamber by varying valve lift, duration, and timing to provide a commensurate air charge for efficient combustion, allowing rapid and efficient modulation of torque output without the inefficiencies associated with ignition timing adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If throttle valve position is controlled to modulate engine output torque, then the system is simple to operate, but the response is delayed due to air volume in the inlet manifold
Solution Approach 1:
The patent replaces the mechanical throttle valve control system with an active tappet system that directly controls inlet valve timing and duration. This substitution eliminates the delay caused by air volume in the inlet manifold, achieving rapid torque modulation while maintaining operational simplicity through electronic control.
Solution Approach 2:
The patent introduces dynamic control of inlet valve timing and duration through an active tappet mechanism. This allows real-time adjustment of air charge volume in the combustion chamber, enabling rapid response to torque demands without the inertial delays inherent in traditional throttle-based systems.
2Speed
If ignition timing is retarded to reduce output torque rapidly, then the response speed is improved, but combustion efficiency deteriorates and waste heat increases
Solution Approach 1:
The patent dynamically adjusts inlet valve timing and duration to control air charge volume, enabling rapid torque modulation without retarding ignition timing. This maintains optimal combustion timing and efficiency while achieving the desired torque reduction, avoiding the energy losses associated with ignition retardation.
Solution Approach 2:
The patent changes the parameters of inlet valve operation (timing and duration) to control the air charge volume in the combustion chamber. This provides a direct mechanism for torque control that preserves combustion efficiency, as the air-fuel mixture quantity is adjusted rather than the ignition timing.
3Speed
If ignition timing is advanced in anticipation of torque-up request, then the response speed is improved, but inefficient combustion occurs with increased emissions
Solution Approach 1:
The patent uses dynamic control of inlet valve timing and duration to anticipate and prepare for torque-up requests by adjusting the air charge volume before combustion. This allows rapid torque response without advancing ignition timing, thereby avoiding the formation of harmful emissions associated with premature combustion.
4Device complexity
If cam element movement is used to vary inlet/exhaust valve operation, then the system is mechanically simple, but the response is slow compared to ignition timing variation
Solution Approach 1:
The patent replaces traditional cam-based mechanical valve control with an active tappet system that uses electronic actuators to control valve timing and duration. This substitution maintains mechanical simplicity while achieving response speeds comparable to ignition timing control, as the active tappet can be rapidly actuated by electronic signals.
Data Source
AI summary
A method and apparatus for continually and rapidly adjusting the output torque of an engine according to a torque demand uses an active tappet to vary the instant air charge in a combustion chamber. The invention allows substantially efficient combustion throughout the engine operating map. Various methods of changing the charge of air are disclosed.