Water Tight Valve Sealing Flying Leads with Adhesive Collar
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solenoid controlled water valves face challenges in achieving a watertight seal for electrical leads due to exposure to conductive fluids and contaminants, as traditional sealing methods fail to adhere effectively to flexible wire insulation, leading to short circuits and dielectric breakdown.
Innovation Solution
A sealing system using an adhesive heat shrink collar on the wire insulation, combined with overmolding of the solenoid terminals and wires with a plastic material like polypropylene, creates a hermetic seal by bonding the collar to both the insulation and the overmolding, preventing fluid ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional sealing methods (adhesives, sealants, ultrasonic methods) are used on flexible wire leads, then the sealing process can be performed, but the seal fails to adhere effectively to the wire insulation due to plasticizers and lubricants in the wire coating, resulting in water tightness deterioration
Solution Approach 1:
The patent introduces a sealing collar as an intermediary component that bonds to both the wire insulation and the overmolded material. This collar acts as a mediator between the two dissimilar materials, providing a reliable bonding interface that prevents fluid ingress while accommodating the challenges of bonding to plasticized wire insulation.
Solution Approach 2:
The solution employs a composite sealing structure consisting of a sealing collar made from materials that are compatible with both the wire insulation and the overmolded material. This composite approach allows the seal to bond effectively to both dissimilar surfaces, overcoming the adhesion problems inherent in bonding directly between wire insulation and overmolded material.
2Object-affected harmful factors
If overmolding is used to encapsulate the solenoid and wire leads, then mechanical protection is provided, but the dissimilar plastics (overmold material and wire insulation) do not bond effectively, allowing conductive fluids to wick down into the joint
Solution Approach 1:
The sealing collar serves as a mediator between the overmolded material and the wire insulation, providing a bonding interface that prevents fluid ingress. The collar is specifically designed to bond to both materials, eliminating the wicking path that would otherwise exist between the dissimilar plastics.
Solution Approach 2:
The sealing collar adds a dimensional element to the seal by creating a protruding barrier that extends beyond the interface between the overmolded material and wire insulation. This dimensional addition blocks the wicking path of conductive fluids, preventing them from reaching the joint between dissimilar plastics.
3Ease of operation
If wire leads are allowed to move and flex for connection to terminals, then electrical connection is achieved, but vibration and movement cause traditional sealing attempts to fail
Solution Approach 1:
The sealing collar is designed as a flexible component that can accommodate the movement and flexing of the wire leads while maintaining its sealing function. The collar's flexibility allows it to move with the wire without compromising the seal integrity, unlike rigid traditional sealing methods.
4Ease of manufacture
If adhesive heat shrink collars are used on wire insulation, then adhesion to insulation is improved, but the collar must also bond to overmolding material to create hermetic seal
Solution Approach 1:
The sealing collar is constructed from composite materials or a multi-layer structure that provides compatibility with both the wire insulation and the overmolded material. This composite construction allows the single collar component to bond effectively to both dissimilar surfaces, creating a hermetic seal without requiring multiple separate sealing components.
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 effectively reduces the occurrence of short circuits and dielectric breakdown by forming a reliable water-tight seal around the wire-terminal connection, even in harsh environments with continuous exposure to conductive fluids.
Implementation Method 1
A sealing collar of adhesive heat shrink is attached to the insulating cover of the wire... bonding the heat shrink collar to both the insulation and overmolding
Implementation Method 2
adhesive heat shrink collars on the wire insulation... heating the collar to shrink it around the insulation
Data Source
AI summary
A water tight valve with sealed flying leads is presented. The sealing is provided by an adhesive heat shrink collar that is affixed to the insulation of the flying leads. An overmolding is used to provide further protection of the terminal/wire contact interface and to seal against the exterior surface of the collar. The profile of the collar also provides a tortuous path that further prevents the ingress of any conductive fluid to the wire/terminal contact area.