Valve Stem Repair Extension for TPMS Corrosion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Corrosion between dissimilar metals in valve stems and TPMS sensors leads to costly and inconvenient repairs, especially in TPMS valve stem assemblies, where the entire assembly must be replaced due to damage, even if the sensor is functional.
Innovation Solution
A valve stem repair extension with a beveled surface is used to create a hermetic seal within the damaged valve stem assembly, allowing for the installation of a new valve stem without replacing the entire assembly, using a countersinking drill bit to enlarge the bore and create internal threads for the repair extension, and optionally including a gasket for enhanced sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a metal valve cap is used on an aluminum valve stem, then the valve cap provides durability and protection, but corrosion occurs between the dissimilar metals leading to valve stem damage
Solution Approach 1:
A rubber grommet is introduced as an intermediary component between the metal valve cap and aluminum valve stem. This grommet prevents direct contact between the dissimilar metals, eliminating the galvanic corrosion pathway while still allowing the valve cap to provide its protective function. The grommet acts as a mediator that maintains the beneficial aspects of metal construction while preventing the harmful corrosion interaction.
2Reliability
If the entire TPMS valve stem assembly is replaced when the valve stem is damaged, then a functional replacement is provided, but the repair becomes expensive and time-consuming
Solution Approach 1:
The valve stem assembly is segmented into separable components: the valve stem body, the valve cap, and the grommet. When corrosion or damage occurs, only the affected components need to be replaced rather than the entire assembly. This segmentation allows for targeted repair of just the valve stem or valve cap while retaining functional components, significantly reducing repair time and cost.
Solution Approach 2:
The design enables selective discarding of only the damaged components (valve stem or valve cap) while recovering and reusing the functional components (sensor, remaining stem portions). This approach contrasts with replacing the entire assembly, allowing technicians to discard only what is necessary and recover valuable functional elements for continued use.
3Reliability
If the entire TPMS valve stem assembly is replaced, then a complete functional replacement is achieved, but the cost of repair increases significantly
Solution Approach 1:
The valve stem assembly is segmented into separable components: the valve stem body, the valve cap, and the grommet. When corrosion or damage occurs, only the affected components need to be replaced rather than the entire assembly. This segmentation allows for targeted repair of just the valve stem or valve cap while retaining functional components, significantly reducing repair time and cost.
Solution Approach 2:
The design enables selective discarding of only the damaged components (valve stem or valve cap) while recovering and reusing the functional components (sensor, remaining stem portions). This approach contrasts with replacing the entire assembly, allowing technicians to discard only what is necessary and recover valuable functional elements for continued use.
4Ease of repair
If the valve stem is designed with separable components, then repair becomes easier and less costly, but the device complexity increases
Solution Approach 1:
The valve stem assembly is segmented into separable components: the valve stem body, the valve cap, and the grommet. When corrosion or damage occurs, only the affected components need to be replaced rather than the entire assembly. This segmentation allows for targeted repair of just the valve stem or valve cap while retaining functional components, significantly reducing repair time and cost.
Solution Approach 2:
A rubber grommet is introduced as an intermediary component between the metal valve cap and aluminum valve stem. This grommet prevents direct contact between the dissimilar metals, eliminating the galvanic corrosion pathway while still allowing the valve cap to provide its protective function. The grommet acts as a mediator that maintains the beneficial aspects of metal construction while preventing the harmful corrosion interaction.
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
This method allows for the repair of damaged valve stems without the need for extensive disassembly and replacement, reducing repair costs and time by creating a functional seal within the existing valve stem assembly, thus extending its lifespan.
Implementation Method 1
a beveled surface adjacent to said threaded attachment portion for creating a hermetic seal between the valve stem repair extension and the valve stem assembly
Implementation Method 2
a threaded attachment portion on one end of said body for mating with a threaded bore in a damaged valve stem assembly; an outer threaded portion on an end of said body opposite said threaded attachment portion for mating with a valve cap
Data Source
AI summary
A method for repairing damaged valve stem assemblies includes enlarging a bore within a body of a valve stem to form an enlarged bore portion and creating a conical hole in an end of the valve stem body around the enlarged bore portion. Internal threads are created within the enlarged bore portion, and a valve stem repair extension is installed in the enlarged bore portion. The valve stem repair extension has a beveled surface that facilitates formation of a hermetic seal between the valve stem body and the valve stem repair extension. The steps of enlarging the bore and creating the conical hole may both be performed using a countersinking drill bit having a beveled cutting portion.