Variable Compression Engine Pressure Device for Clearance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Variable volumetric ratio engines face challenges in maintaining precise clearances between moving components and the cylinder block, leading to acoustic emissions and potential engine destruction due to temperature variations and manufacturing difficulties, which require high precision and adjustment complexity.
Innovation Solution
A pressing device that maintains raceways of main moving components in permanent contact with the cylinder block using pressure means such as helical springs, Belleville washers, or hydraulic pressing rams, ensuring zero clearance and adjustable stops to manage temperature variations and reduce acoustic emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high precision manufacturing is used for the cylinder block and adjustment shims, then the maximum operating clearance between raceways is reduced, but the manufacturing cost increases
Solution Approach 1:
A pressing device is introduced as an intermediary component between the moving components and the cylinder block. This device actively maintains permanent contact between raceways through applied pressure, serving as a mediator that compensates for clearance issues without requiring high-precision manufacturing of the cylinder block itself.
Solution Approach 2:
The pressing device changes the physical state of contact between components by applying continuous pressure force. This transforms the clearance parameter from a fixed geometric dimension (requiring high precision) to a dynamically controlled parameter (maintained by pressure), allowing standard manufacturing tolerances to be used.
2Object-generated harmful factors
If high precision manufacturing is used for the cylinder block and adjustment shims, then acoustic emissions are reduced, but the manufacturing complexity increases
Solution Approach 1:
The pressing device acts as an intermediary that actively manages the contact conditions between components. By maintaining permanent contact through pressure, it eliminates clearance-induced hammering and acoustic emissions without requiring complex high-precision manufacturing processes.
Solution Approach 2:
The pressing device applies pressure in advance to prevent clearance formation before it can cause acoustic emissions. This preliminary action of maintaining contact prevents the harmful effect from occurring in the first place, rather than requiring complex manufacturing to prevent clearance.
3Speed
If the control rack movement speed is increased to improve volumetric ratio adjustment, then the response time is reduced, but the risk of exceeding force limits increases
Solution Approach 1:
The pressing device provides dynamic pressure adjustment capability, allowing the system to adapt force levels during operation. This enables faster control rack movement when needed while maintaining force limits through active pressure control, transforming a static force constraint into a dynamic one.
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 reduces acoustic emissions, eliminates risks of engine destruction, and enhances the efficiency of adjusting the compression ratio, while simplifying the manufacturing process and increasing the speed of the control rack's movement to increase the volumetric ratio.
Implementation Method 1
pressure means such as helical springs, Belleville washers, or hydraulic pressing rams
Implementation Method 2
pressure means such as helical springs, Belleville washers, or hydraulic pressing rams
Data Source
AI summary
A pressure device maintains the raceways (48, 160 to 165) of the main moving components (3, 5, 7 and 40) of a variable compression ratio engine permanently in contact with one another and with the faces on which they rest in a cylinder case. The inventive device includes pressure elements which are solidly connected to the cylinder case (100) and which exert a pressure force on a control rack (7) having a toothed segment (75) formed by teeth (74). The pressure force is applied against a support surface (78) provided on the lower part of the rack (7).