Hollow Test Body With Threaded Nozzle For Material Testing

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Solution Overview

Problem

Existing test specimens for material testing are not suitable for secure and simple attachment during bursting and tensile tests, limiting their application and accuracy in characterizing material properties, especially for plastic components.

Innovation Solution

A hollow tubular test body with a nozzle-shaped inlet area featuring an external or internal thread for secure attachment, allowing for injection-molded geometries that can perform both tensile and bursting tests, enabling a direct correlation between bursting pressure and mechanical strengths, and accommodating various material aging states and geometries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a hollow cylindrical test body is used for material testing, then the test specimen can be used for ultrasonic crack propagation measurements, but it is not suitable for bursting and tensile tests due to lack of attachment features

Engineering Contradiction:
Improveapplicability for different test typesVSAvoidspecimen geometry complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The test body is designed with multiple functional features integrated into a single geometry: the hollow cylindrical shape enables ultrasonic crack propagation measurements, while the integrated threads at the ends enable bursting and tensile tests. This multi-functional design allows one specimen geometry to serve multiple testing purposes, resolving the contradiction between versatility and complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If threads are added to the test body for secure attachment during bursting and tensile tests, then attachment security is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveattachment securityVSAvoidspecimen manufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The threads are integrated directly into the test body geometry during the same manufacturing process (injection molding) that creates the hollow cylindrical shape. By combining the attachment features with the main specimen structure in a single manufacturing step, the patent achieves secure attachment without significantly increasing manufacturing complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the pipe has a larger diameter in the threaded nozzle area compared to the middle test range, then secure attachment is enabled, but the wall thickness varies along the length

Engineering Contradiction:
Improveattachment securityVSAvoiduniform wall thickness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The test body features localized variations in diameter and wall thickness: the middle section maintains uniform dimensions for consistent mechanical testing, while the end sections (nozzles) have larger diameters and increased wall thickness to accommodate threads and provide secure attachment. This local differentiation optimizes each region for its specific function while maintaining manufacturability through injection molding.

Inventive Principle:
Principle #3Local quality

4Adaptability or versatility

If injection-molded tubular test specimen geometries with molded threads are used, then a wide variety of materials and aging states can be tested in the same geometry, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvematerial comparison capabilityVSAvoidinjection molding complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The injection molding process is configured to produce a universal test body geometry that can accommodate different materials (thermoplastics, coatings, 2-component solutions) and aging states. The molded threads and hollow cylindrical shape remain consistent across all material types, enabling direct comparison while maintaining a relatively simple single-step manufacturing process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP1772721B1Hollow test body
Publication Date: 2013.04.03 WILO SE
  • EP1772721B1 patent drawingFigure 1

AI summary

The hollow test body (1) has an inlet for an inspection part cavity. The inlet part is formed as a connecting piece (3, 4) having an external or an internal thread (7, 8) for fastening to a testing set. Near the threaded end a pipe or tube is provided having a larger outside diameter (D1) and or a larger wall thickness than in the middle part. The body may tubular or spherical. One end of the tube end may be sealed with the other end be threaded. Both tube ends may be threaded. An independent claim is included for a method.