Self-Contained Hydraulic Compression Ratio Adjustment Mechanism
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Solution Overview
Problem
Existing solutions for adjusting the compression ratio of internal combustion engines are inefficient, sensitive to engine speed and temperature, and require complex external control systems, leading to energy losses and reduced reliability.
Innovation Solution
A self-contained device within the engine, comprising high- and low-pressure hydraulic chambers and calibrated conduits, allows for autonomous adjustment of the compression ratio by controlling the position of the combustion piston, using mechanical return means to maintain a predetermined compression ratio based on average combustion forces, thereby reducing wear and improving reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a hydraulic chamber with spring is used to adjust compression ratio, then the compression ratio can be varied with load, but the system becomes sensitive to engine speed and temperature, reducing reliability
Solution Approach 1:
The connecting rod autonomously adjusts the compression ratio by utilizing the combustion forces and inertial forces it already experiences during engine operation. The rod self-regulates its length based on the load conditions without requiring external control systems, sensors, or actuators, thereby eliminating the sensitivity to engine speed and temperature that plagues externally controlled systems.
Solution Approach 2:
The invention extracts the control function from external systems and embeds it directly into the connecting rod structure itself. By integrating the compression ratio adjustment mechanism within the rod, the system eliminates the need for complex external hydraulic chambers, springs, and control systems that are sensitive to operating conditions.
2Adaptability or versatility
If external control systems are used to adjust compression ratio, then the compression ratio can be controlled, but energy losses increase and reliability decreases
Solution Approach 1:
The connecting rod utilizes the combustion forces and inertial forces already present in the engine to drive the compression ratio adjustment. No additional energy input or external control systems are required, eliminating the energy losses associated with hydraulic pumps, motors, and control electronics found in externally controlled systems.
3Adaptability or versatility
If complex external control systems are used for compression ratio adjustment, then the compression ratio can be varied, but device complexity increases
Solution Approach 1:
The invention merges the compression ratio adjustment function with the connecting rod structure itself. The rod integrates the control mechanism, actuation system, and sensing function into a single unified component, eliminating the need for separate external control systems, hydraulic chambers, springs, and actuators.
Solution Approach 2:
The connecting rod performs multiple functions simultaneously: it transmits combustion forces, manages inertial forces, and autonomously adjusts the compression ratio based on operating conditions. This multi-functionality eliminates the need for dedicated control systems, reducing overall device complexity.
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 enables efficient, autonomous adjustment of the compression ratio, reducing mechanical stress and energy losses, while maintaining reliability across varying engine conditions and temperatures.
Implementation Method 1
a high-pressure hydraulic chamber to counteract the combustion and inertial forces at the bottom dead center; a low-pressure hydraulic chamber to counteract the inertial forces at the top dead center
Data Source
AI summary
A variable compression ratio engine comprises a stationary engine block in which movable members interact to enable a piston to translate in a combustion cylinder of the engine block, defining a stroke of the combustion piston. The engine further comprises a self-contained device for adjusting a position of a top dead center of the combustion piston, the self-contained device being connected to or built into at least one of the movable members and having a high-pressure hydraulic chamber to counteract the combustion and inertial forces at a bottom dead center, a low-pressure hydraulic chamber to counteract the inertial forces at the top dead center, at least one calibrated conduit to enable hydraulic fluid to flow between the high- and low-pressure hydraulic chambers, and return means to bring the device back to a nominal position.