Offset-Axis Throttle Valve Spherical Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing throttle valve devices for internal combustion engines face challenges in achieving tight closure and precise fluid control, especially with small adjustment angles, due to manufacturing complexities and high costs associated with precise machining and sealing, and limitations in assembly injection molding processes.
Innovation Solution
The throttle valve device features a radially and axially offset axis of rotation with a spherical peripheral surface that contacts the housing seat, allowing for tight sealing without additional components and enabling cost-effective assembly injection molding, while avoiding undercuts and allowing for precise fluid control through adjustable channel sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If precise machining and sealing compounds are used to achieve tight closure, then sealing performance is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The throttle body is designed with a spherical peripheral surface that contacts a corresponding seat in the housing, creating a natural sealing interface through curved geometry. This spherical contact surface eliminates the need for additional sealing compounds or complex machining while ensuring tight closure through the inherent conformability of spherical contact.
Solution Approach 2:
The throttle body's spherical peripheral surface automatically seals against the housing seat through its geometric design, without requiring external sealing components or compounds. The self-sealing mechanism is achieved through the precise spherical contact geometry that naturally conforms to the mating surface, eliminating the need for separate sealing systems.
2Ease of manufacture
If assembly injection molding is used to reduce manufacturing cost, then ease of manufacture is improved, but achieving tight sealing becomes difficult
Solution Approach 1:
The spherical peripheral surface of the throttle body provides a geometric sealing interface that can be directly formed during injection molding. The curved spherical geometry allows for tight sealing through the natural conformability of the spherical contact, eliminating the need for post-molding sealing operations while maintaining compatibility with cost-effective injection molding processes.
3Ease of manufacture
If the axis of rotation is offset radially to enable assembly injection molding, then ease of manufacture is improved, but control precision with small adjustment angles deteriorates
Solution Approach 1:
The channel cross-section is designed to widen in the axial direction from the seat surface to the axis of rotation, creating an expanded flow control zone. This axial dimension expansion compensates for the radial offset of the rotation axis, providing sufficient leverage and control authority for precise fluid quantity regulation even with small throttle body adjustment angles.
4Measurement precision
If spherical zones are added to the housing to improve fluid control characteristics, then measurement precision is improved, but manufacturing complexity increases due to undercuts
Solution Approach 1:
Instead of adding spherical zones to the housing, the patent achieves precise fluid control by designing the channel cross-section to widen axially from the seat surface to the axis of rotation. This axial expansion creates the necessary flow control characteristics without introducing radial undercuts, maintaining compatibility with simple injection molding processes.
Data Source
Figure 1~3
Figure 4~7
Figure 8~9
AI summary
A throttle plate pivots about a pivot axis through a positioning device to close or open a bore (2) relative to a seat face (8) formed by the inner wall (9) of the housing (1). The pivot axis is offset with respect to the plate so that one throttle blade (5) pivots away from the cross-section of the bore and the other blade pivots towards the cross-section of the bore when the bore is opened. A radial peripheral surface (7) of the plate is formed as a sphere in section so that the peripheral surface of the plate abuts the seat face with linear contact in the position closing the bore.