Eccentric Shutter Throttle Valve Asymmetry
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Solution Overview
Problem
Current throttle valves in internal combustion engines face challenges with air leakages, thermal expansion issues, and increased costs due to the need for precise construction tolerances, which are exacerbated by downsizing engines and the obstacle they pose to air flow, leading to inefficiencies and higher production costs.
Innovation Solution
A throttle valve design featuring a tubular supply conduit with an eccentrically arranged shutter that rotates asymmetrically, allowing for non-symmetrical movement and reduced contact areas, combined with a labyrinth seal to minimize leaks and made from affordable materials like plastic, reducing the need for precise dimensions and thermal expansion matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the throttle plate is made with the same shape and size as the internal section of the supply conduit to ensure sealing, then air leakage is reduced, but the construction accuracy requirements and manufacturing costs increase significantly
Solution Approach 1:
The shutter is designed with an asymmetric shape that does not match the circular internal section of the supply conduit. The shutter has a contact area that is smaller than the full conduit cross-section, creating an asymmetric sealing interface. This asymmetry allows the shutter to seal the conduit without requiring the shutter to be the exact same shape and size as the conduit, thereby reducing manufacturing precision requirements while maintaining sealing performance.
2Productivity
If the swept volume of internal combustion engines is downsized to reduce fuel consumption, then fuel efficiency improves, but air leakage becomes more significant and requires more precise throttle valve control
Solution Approach 1:
The asymmetric shutter design creates a more precise sealing interface with the supply conduit. The non-circular shape of the shutter contact area provides a more defined sealing geometry that reduces air leakage paths. This enhanced sealing precision is particularly beneficial for downsized engines where even small leakages have significant impact, allowing for better air flow control without requiring excessively tight manufacturing tolerances.
3Ease of operation
If a traditional throttle valve design is used to control air flow, then air flow adjustment is achieved, but the throttle valve creates significant flow obstruction and load losses
Solution Approach 1:
The asymmetric shutter design allows for optimized flow paths when the throttle valve is in partially open positions. The non-circular shape and eccentric mounting create more favorable airflow characteristics compared to a traditional symmetric throttle plate, reducing turbulence and flow separation. This reduces energy losses while maintaining the ability to control air flow across the full range from closed to fully open positions.
Data Source
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AI summary
Throttle valve (1) for an internal combustion engine; the throttle valve(1) having: a supply conduit (2); and a shutter (3), which engages the supply conduit (2) and rotates about an axis of rotation (4) between a closed position and a fully open position of the supply conduit (2); the axis of rotation (4) of the shutter (3) is eccentrically arranged with respect to a center (9) of the shutter (3).