Elastic Joint Bi-Material Injection for Adhesive-Free Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing elastic joints, such as those used in the automotive industry, rely on adhesives for connecting components, which are costly and environmentally hazardous, and mechanical assembly can be time-consuming and prone to deformation.
Innovation Solution
A bi-material injection molding process that uses a single mold to create an elastic joint with an external ring, internal ring, and intermediate element, where the intermediate element is molded while the external and internal rings are still warm, forming a chemical bond without adhesives, using polyamide for the rings and thermoplastic polyurethane for the intermediate element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive is used to glue the outer ring and inner ring onto the intercalated element, then the connection reliability is improved, but the manufacturing cost increases and environmental hazards are introduced
Solution Approach 1:
The patent removes the adhesive substance from the manufacturing process entirely. Instead of using chemical adhesives to bond the intercalated element to the outer and inner rings, the invention extracts this harmful element and replaces it with a mechanical interference fit achieved through precise dimensional control and geometric design of the components.
Solution Approach 2:
The patent replaces the chemical bonding system (adhesive) with a mechanical bonding system. The intercalated element is designed with geometric features that create a mechanical interference fit with the rings, achieving reliable connection through mechanical interlocking rather than chemical adhesion.
2Object-affected harmful factors
If mechanical assembly is used to connect the outer ring and inner ring onto the interlayer element, then the use of adhesive is avoided, but the assembly time increases and deformation may occur
Solution Approach 1:
The patent merges the molding of the outer ring, inner ring, and intercalated element into a single integrated injection molding process. All three components are formed and assembled in one continuous operation within the same mold, eliminating the need for separate assembly steps and reducing total manufacturing time.
Solution Approach 2:
The patent incorporates preliminary action by designing the mold to include all necessary geometric features and dimensional tolerances that enable the interference fit to be achieved automatically during the injection molding process. The components are pre-configured in the mold with precise positioning features that ensure proper alignment and fit without requiring post-molding assembly operations.
3Object-affected harmful factors
If mechanical assembly is used instead of adhesive, then adhesive cost is reduced, but the connection rigidity and resistance to deformation deteriorate
Solution Approach 1:
The patent applies local quality by designing specific geometric features on the intercalated element and rings that concentrate the mechanical interlocking action at critical locations. The interference fit is optimized at the interface between the intercalated element and each ring, with localized geometric features that enhance connection rigidity and resistance to deformation at these critical joints.
Solution Approach 2:
The patent employs composite material design by combining the intercalated element material with the ring materials in a way that creates complementary mechanical properties. The material selection and geometric design work together to achieve a composite structure that provides both flexibility for vibration damping and sufficient rigidity for structural connection without requiring adhesive.
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 ensures a reliable, adhesive-free connection between components, reducing assembly time and potential deformation, while utilizing environmentally friendly materials with improved mechanical resistance and filtration characteristics.
Implementation Method 1
forming a chemical bond without adhesives
Implementation Method 2
where the intermediate element is molded while the external and internal rings are still warm
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a method for manufacturing an elastic joint (10a, 10b) comprising an outer ring (12a, 12b) extending axially around a joint axis and intended to be connected to a first articulated element, an inner ring (28a, 28b) extending axially along the joint axis within the outer ring (12a, 12b) and intended to be connected to a second articulated element, and an elastically deformable intermediate element (16b) that connects the inner ring (28b) to the outer ring (12b), allowing axial and radial mobility of the inner ring (28b). The method is characterized in that it comprises at least one molding step of the outer ring (12a, 12b) and the inner ring (28a, 28b) of the joint (10a, 10b), which consists of injecting a first material in a first cavity (56) of a mold (50), and a molding step of the intermediate element (16b) of the joint (10b),which consists of injecting a second material into a second cavity (58) of said mold (50) between the outer ring (12b) and the previously formed inner ring (28b).