Automotive Hose Rigid Element Plastic Injection Molding
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Solution Overview
Problem
Existing hoses for air conditioning and power steering circuits in motor vehicles are cumbersome and costly to manufacture due to the use of metal tubes, which also generate undesirable metallic shavings during shaping.
Innovation Solution
The use of plastic material for rigid tubular elements with integrated sealing gaskets and metal inserts for crimping, allowing for injection molding and bi-injection processes to reduce costs and simplify assembly, while providing mechanical reinforcement and preventing collapse during crimping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal tubes are used for rigid tubular elements, then mechanical strength and compression resistance are improved, but manufacturing cost and assembly complexity increase
Solution Approach 1:
The patent uses a composite structure combining plastic material for the rigid tubular element body with integrated metal inserts at connection ends. The plastic provides cost-effective manufacturing through injection molding, while the metal inserts provide necessary compression resistance for crimping operations, resolving the contradiction between manufacturing cost and mechanical strength.
Solution Approach 2:
The patent applies different materials to different parts of the rigid tubular element: plastic material for the main body where cost-effective molding is advantageous, and metal inserts specifically at connection ends where compression resistance during crimping is critical. This localized application of material properties resolves the contradiction between overall manufacturing cost and localized strength requirements.
2Ease of manufacture
If metal tubes are shaped and machined, then connection ends can be formed, but metallic shavings are generated causing contamination
Solution Approach 1:
The patent replaces traditional mechanical shaping and machining operations for metal tubes with injection molding of plastic material. This substitution eliminates the generation of metallic shavings during forming operations, as plastic injection molding is a non-contact, non-erosive process that directly forms parts without material removal.
Solution Approach 2:
The patent changes the material parameter from metal to plastic, which fundamentally alters the manufacturing process parameters. Instead of cutting, bending, and machining metal operations that generate shavings, the process uses injection molding parameters (temperature, pressure, injection rate) to form parts without material removal, eliminating shavings generation.
3Ease of manufacture
If plastic material is used for rigid tubular elements, then manufacturing cost and shaping ease are improved, but compression resistance during crimping deteriorates
Solution Approach 1:
The patent creates a composite structure where plastic material forms the main body of the rigid tubular element, providing cost-effective manufacturing, while metal inserts are integrated at connection ends to provide the necessary compression resistance for crimping operations. This composite approach resolves the contradiction between manufacturing cost and compression resistance.
Solution Approach 2:
The metal inserts act as intermediary elements between the plastic rigid tubular element and the crimping sleeve. These inserts provide the hard, compression-resistant interface needed for crimping while being embedded in the softer plastic material, allowing the plastic body to maintain its cost advantage while the metal inserts handle the high-stress crimping operation.
4Reliability
If metal tubes are used, then connection strength is ensured, but assembly operations become cumbersome and time-consuming
Solution Approach 1:
The patent merges the rigid tubular element body (molded in plastic) with integrated sealing gaskets and connection features into a single injection-molded component. This consolidation eliminates multiple separate parts and assembly steps required with traditional metal tube constructions, improving assembly speed while maintaining connection strength through the integrated design and metal inserts.
Solution Approach 2:
The sealing gaskets and connection features are pre-formed as integral parts of the rigid tubular element during injection molding, before assembly. This preliminary formation of sealing and connection features eliminates the need for separate gasket installation and machining operations during assembly, thereby increasing productivity while ensuring reliable connections.
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 reduces manufacturing costs, simplifies the shaping of curved sections, and prevents breakage during crimping, resulting in a more efficient and cost-effective hose production process with fewer parts and less material waste.
Implementation Method 1
this plastic material makes it possible to shape the or each rigid tubular element by means of injection molding, thus facilitating the obtaining of one or more curved sections for each of these elements with a radius of curvature predetermined by the imprint of the mould
Implementation Method 2
an elastomer seal molded into a groove of the rigid element, radially between the latter and the flexible element
Implementation Method 3
a hose comprising at least one rigid tubular element connected in one at least its connection ends to a flexible tubular element via a crimping of a metal sleeve
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The hose (1) has intermediate and end rigid tubular elements (4, 5) that are realized by a plastic material, where the elements have a connecting end coated with a sealing lining or mechanical decoupling lining. The sealing lining is extended on an external radial face of an axial connecting end, or the mechanical decoupling lining is passed through a bracket (8) forming a radial connecting end at the rigid elements. The element (4) is connected to a flexible tube (2) by a crimping socket (6).