Hose Coupling Nipple Rib Profile for Leak-Safe Press Fitting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-pressure hydraulic hose couplings often experience micro-cracks in the inner hose due to elongation stresses during the installation of a press-fit ferrule, leading to a compromised seal.
Innovation Solution
A coupling part design featuring a rib profile with symmetrical and asymmetrical groove sections, where the asymmetrical grooves have a greater volume, reduces stress on the inner hose and provides sufficient holding capacity, ensuring a secure connection with minimal resistance during ferrule push-on and pull-off, while promoting a good sealing effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a press-fit ferrule is pushed onto the hose nipple during installation, then a firm connection of the high-pressure hydraulic hose to the coupling element is achieved, but elongation stresses occur in the inner hose which can lead to micro-cracks and compromise the seal
Solution Approach 1:
The rib profile features asymmetrical grooves with different groove volumes in different sections. The first profile section has grooves with smaller groove volume while the second profile section has grooves with greater groove volume. This asymmetrical design allows the grooves to effectively accommodate and redirect hose material during the push-on process, reducing elongation stresses that cause micro-cracks while maintaining connection firmness.
Solution Approach 2:
Different sections of the rib profile have different groove characteristics tailored to local requirements. The first profile section (facing the connection head) has symmetrical grooves with smaller volume for initial guidance, while the second profile section has asymmetrical grooves with greater volume for stress reduction during ferrule installation. This localized differentiation optimizes both sealing and stress distribution.
2Reliability
If the grooves have sufficient holding capacity to prevent pull-off, then the connection reliability is improved, but the resistance to pushing the hose section onto the press-fit nipple increases
Solution Approach 1:
The asymmetrical groove design creates different resistance characteristics in different sections. The grooves in the second profile section have greater volume and are configured to provide strong holding capacity against pull-off forces, while the asymmetrical shape allows hose material to flow into the grooves more easily during the push-on process, reducing installation resistance.
Solution Approach 2:
The rib profile differentiates groove characteristics between sections: the first profile section has grooves optimized for guidance with lower resistance, while the second profile section has grooves with greater volume optimized for pull-off inhibition. This local differentiation resolves the contradiction between holding capacity and push-on ease.
Data Source
AI summary
A coupling part for a hose coupling, in particular for high-pressure hydraulic lines, and a hose coupling having such coupling part, has a connection head for connecting to a fitting, and, formed on the connection head, a press-fit nipple, which is intended for accommodating a hose-end portion, on which a pushed-on hose-end portion can be fastened in a sealing manner by pressing action by an at least partially sleeve-form press-fit ferrule enclosing the hose-end portion, and which has a rib profile including ribs bounded by grooves. The rib profile has at least two profile portions. The grooves of the first profile portion, which is directed towards the connection head, have a symmetrical cross section and the grooves of the second profile portion have an asymmetrical cross section and a larger groove volume than the grooves of the first profile portion.