Solenoid Switch Protective Cap Labyrinth Sealing for Pressure Equalization
Solution Overview
Problem
Existing starter relays for internal combustion engines fail to maintain functionality due to pressure buildup from rapid heating, leading to potential water and dirt ingress through conventional protective caps, which compromise the sealing integrity and starter performance.
Innovation Solution
The introduction of strategically designed gaps and labyrinthine sealing structures in the protective cap, with adjustable interruptions and angular offsets, allows for controlled pressure equalization while preventing media ingress, ensuring reliable operation under temperature fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hole is made in the protective cap for pressure equalization, then the relay can switch after rapid heating, but water and dirt can enter the relay
Solution Approach 1:
The protective cap is segmented with multiple small gaps distributed around its circumference rather than a single large hole. These gaps are arranged in a labyrinthine pattern that forces media to change direction multiple times, providing pressure equalization while blocking water and dirt ingress.
Solution Approach 2:
The sealing rings are interrupted to create gaps that extend in the axial direction, forming a labyrinthine structure. This three-dimensional arrangement allows air to pass through while preventing media from penetrating radially into the relay interior.
2Object-affected harmful factors
If the protective cap is made completely sealed, then protection against water and dirt is maximized, but pressure buildup prevents switching after rapid heating
Solution Approach 1:
The protective cap has different sealing qualities in different regions: the gaps are positioned and sized to allow pressure equalization while the overall structure maintains high sealing quality to block water and dirt. The labyrinthine arrangement creates localized pressure relief paths that do not compromise overall protection.
3Stress or pressure
If a large hole is made in the protective cap, then pressure equalization is effective, but the cross-section for media ingress is increased
Solution Approach 1:
Instead of a single large hole, the protective cap incorporates multiple small gaps distributed around its circumference. These gaps collectively provide sufficient cross-sectional area for pressure equalization while each individual gap remains too small to allow significant media ingress.
Solution Approach 2:
The gaps are arranged in a curved, labyrinthine pattern around the protective cap rather than in straight lines. This curved arrangement increases the path length that media must travel while maintaining a compact overall structure, improving pressure equalization without increasing the effective opening size.
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 solution effectively reduces the risk of starter relay failure from thermal stress while maintaining protection against splash water, ensuring consistent performance by maintaining pull-in voltage below critical levels and preventing media penetration.
Implementation Method 1
If the relay is heated up quickly by the engine, e.g. when driving with a high load (trailer or engine speed) or when the ambient air pressure drops rapidly when driving uphill, the air in the relay expands
Implementation Method 2
the magnet armature is drawn in by a magnetic field that is generated in the magnet windings and presses the switching axis with the contact bridge onto the contacts
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
The invention relates to a solenoid switch for starting devices for starting internal combustion engines, comprising a joint (100) between assembled parts of the solenoid switch. The invention is characterised in that the joint is formed in such a way that a direct penetration of spray water is prevented and pressure compensation is enabled.