Engine Torque Control During Cylinder Deactivation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine technologies face challenges in controlling engine torque and improving fuel efficiency during cylinder deactivation in variable displacement engines, particularly at low load conditions, as retarding spark timing increases fuel consumption and cylinder charge.
Innovation Solution
Adjusting the position of an engine volumetric efficiency actuator and a central throttle to maintain airflow while deactivating cylinders, reducing spark retardation and optimizing engine airflow control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If spark timing is retarded to control engine torque during cylinder deactivation, then engine torque control is improved, but fuel consumption increases
Solution Approach 1:
The patent changes the parameter of spark timing from retarded (conventional) to advanced timing during cylinder deactivation. This parameter change allows the active cylinders to compensate for torque loss more efficiently, reducing the need for excessive spark retard and thereby lowering fuel consumption while maintaining torque control.
Solution Approach 2:
The patent applies preliminary action by adjusting the spark timing advance before cylinder deactivation occurs. By pre-positioning the spark timing in the active cylinders, the system prepares for torque compensation, reducing the need for corrective spark retard after deactivation and minimizing fuel consumption increases.
2Power
If cylinder charge is increased to maintain torque during deactivation, then engine torque is maintained, but fuel consumption increases
Solution Approach 1:
The patent changes the parameter of cylinder charge management by controlling intake valve timing and duration in the active cylinders. This allows precise control of charge quantity to match torque requirements without excessive charge accumulation, thereby maintaining torque while reducing fuel consumption compared to conventional approaches.
3Use of energy by moving object
If cylinders are deactivated to improve fuel consumption, then fuel efficiency is improved, but engine torque control becomes difficult
Solution Approach 1:
The patent applies parameter changes by adjusting spark timing, valve timing, and valve duration parameters in the active cylinders following deactivation. These coordinated parameter adjustments enable the active cylinders to compensate for torque loss, maintaining engine torque control while preserving fuel efficiency benefits of cylinder deactivation.
Solution Approach 2:
The patent implements dynamics by making the engine system adaptable through real-time adjustment of multiple parameters (spark timing, intake valve timing, intake valve duration) based on cylinder deactivation state. This dynamic control allows the system to maintain optimal torque control across varying operating conditions while benefiting from deactivation.
Data Source
AI summary
Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, a position of one or more volumetric efficiency control devices is changed in response to a request to deactivate one or more engine cylinders while at the same time the engine central throttle is adjusted. Spark timing may also be adjusted if engine air flow deviates from a desired engine air flow.