Movable Fulcrum Piston Lever for Engine Stroke Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines face challenges in optimizing the four engine strokes for fuel efficiency, power, and emission control, particularly in maintaining linear piston motion within the cylinder axis while minimizing lateral movement and reducing wear and friction.
Innovation Solution
A robotic arm assembly with a guide apparatus, including a four-bar-linkage and actuator mechanism, is used to control the piston lever and stem, ensuring linear motion along the cylinder axis through a pantographic mechanism, reducing lateral movement and stress, and optimizing piston strokes with electronic control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional fixed fulcrum is used in the piston lever mechanism, then the structure is simple and easy to manufacture, but the piston experiences lateral movement and thrust causing increased wear and friction
Solution Approach 1:
The fulcrum point on the piston lever is made movable instead of fixed, allowing it to shift position dynamically during piston operation. This dynamic adjustment enables the piston lever to maintain optimal geometry and minimize lateral thrust on the piston, thereby reducing wear and friction while accepting increased mechanism complexity
Solution Approach 2:
The position parameter of the fulcrum point on the piston lever is changed from fixed to variable. By allowing the fulcrum to move along the piston lever, the system optimizes the lever arm ratios and angle of action throughout the stroke, reducing lateral forces and improving reliability
2Productivity
If the piston lever is actuated to optimize stroke variation, then fuel efficiency and power optimization are improved, but lateral movement of the piston increases causing more wear and friction
Solution Approach 1:
The piston lever mechanism incorporates a movable fulcrum that dynamically adjusts during operation to compensate for lateral movement caused by stroke variation. This allows the system to maintain optimized stroke lengths for fuel efficiency and power while minimizing harmful lateral thrust through real-time geometric adjustment
Solution Approach 2:
The movable fulcrum acts as an intermediary element between the piston stem and the piston lever body. It mediates the forces and motions, allowing stroke optimization while reducing the transmission of lateral forces to the piston, thereby resolving the conflict between productivity and harmful factors
3Object-affected harmful factors
If a movable fulcrum mechanism is implemented, then lateral thrust is minimized reducing wear and friction, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The piston lever is segmented into distinct functional zones: a movable fulcrum region that allows lateral adjustment, a piston stem coupling region, and an actuation region. This segmentation enables the movable fulcrum mechanism to be integrated into existing engine architectures with minimal modification to other components, easing manufacturing
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An engine includes an engine shaft configured to rotate and cause one or more pistons to reciprocate within a cylinder chamber along an axis, each piston having a first piston part and piston stem to move in unison with or separately from a second piston part to define piston strokes for different thermal functions of the engine. The engine further includes a piston lever having a first end coupled to a movable fulcrum point and a second end coupled at a copy point to the piston stem, an actuation mechanism configured to move the piston lever and thereby the copy point, and a guide apparatus configured to dictate movement of the copy point in a direction substantially parallel to the cylinder axis.