Valve Stem Retention Member for Tire Pressure Sensor Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current tire pressure monitoring systems (TPMS) face challenges in maintaining accurate tire inflation pressure and preventing air leakage due to movement-induced forces during vehicle operation, particularly at high speeds and low temperatures.
Innovation Solution
A valve stem assembly with a retention member that includes a base member and a standoff, allowing for selective movement between two radial positions to minimize movement and maintain a secure seal, thereby preventing air leakage and ensuring accurate pressure monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the valve stem is allowed to move freely within the wheel assembly, then ease of installation is improved, but air leakage increases and tire pressure monitoring reliability deteriorates
Solution Approach 1:
The retention member incorporates a movable standoff that can transition between retracted and extended positions. During installation, the standoff is retracted to allow free movement of the valve stem through the grommet. Once installed, the standoff extends to limit further movement, thus providing both ease of installation and reliable sealing.
Solution Approach 2:
The retention member is designed as a separate component attached to the valve stem body, distinct from the grommet and valve stem. This segmentation allows the retention member to perform its specific function of limiting movement without interfering with the sealing function of the grommet or the operational function of the valve stem.
2Reliability
If a retention member with standoff is added to the valve stem assembly, then reliability of sealing is improved, but device complexity increases
Solution Approach 1:
The retention member combines multiple functions into a single component: the base member attaches to the valve stem body, while the standoff provides the movement-limiting function. This merging reduces the need for separate components and simplifies the overall assembly process despite adding functionality.
Solution Approach 2:
The standoff is designed to be selectively movable, allowing it to automatically retract during installation and extend during operation without requiring external actuation mechanisms. This self-service capability reduces complexity by eliminating the need for motors, sensors, or complex mechanical actuation systems.
3Reliability
If the standoff is positioned at a greater radial distance, then movement limitation is improved, but interference with grommet sealing may occur
Solution Approach 1:
The standoff transitions from a retracted position during installation to an extended position during operation. In the retracted position, it does not interfere with the grommet sealing. When extended, it reaches the optimal radial distance to effectively limit valve stem movement without causing excessive friction or interference with the sealed interface.
Data Source
AI summary
A valve stem connectible to a tire pressure sensor includes a valve stem body and a grommet attached to the valve stem body. The grommet includes a first flange and a second flange extending radially outward from the valve stem body. A retention member attached to the valve stem body includes a base member and a standoff extending from the base member. The standoff is selectively moveable between a first position in which a distal end of the standoff is disposed at a first radial distance from a longitudinal axis of the valve stem body, and a second position in which the standoff is disposed at a second radial distance from the longitudinal axis, the first radial distance being greater than the second radial distance. An outer peripheral edge of the second flange is disposed at a third radial distance that is less than the first radial distance.