Rebound Hardness Tester Indenter Ejection Mechanism

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional rebound hardness testers, such as Shore and Leeb hardness tests, face limitations when measuring small and light specimens due to the 'mass effect,' where kinetic energy is consumed by vibrations, leading to inaccurate hardness readings, and are restricted in testing direction.

Innovation Solution

An apparatus with a spherical indenter held by a tubular holder, featuring an ejection mechanism and speed measuring unit using optical sensors to calculate the coefficient of restitution, allowing for reduced mass effect and free-direction testing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional rebound hardness tester with a heavy hammer or impact body is used, then the testing structure is simple and portable, but the mass effect occurs when measuring small and light specimens, causing kinetic energy to be consumed by vibrations and leading to inaccurate hardness readings

Engineering Contradiction:

Improvehardness measurement accuracyVSAvoidimpactor mass

Core Design Contradiction:

Measurement precisionVSWeight of moving object

Solution Approach 1:

The invention extracts the indenter from the heavy impactor body, using only the lightweight indenter (without the hammer or impact body) to impact the specimen. This eliminates the mass effect caused by heavy impactors while maintaining the rebound hardness testing functionality, thereby improving measurement accuracy for small and light specimens

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention segments the conventional impactor into two parts: the heavy impactor body (hammer or impact body) and the lightweight indenter. By separating these components and using only the indenter for impact, the solution reduces the impacting mass to minimize vibrations and energy loss, thus improving hardness measurement precision

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If a conventional rebound hardness tester is used, then the testing method is simple and quick, but the testing direction is restricted and cannot perform free-direction testing

Engineering Contradiction:

Improvetesting direction flexibilityVSAvoidtesting apparatus structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention employs a dynamic ejection mechanism that can propel the indenter in various directions rather than being fixed in a single orientation. This dynamic capability allows the apparatus to perform testing in any direction (free-direction testing) while maintaining operational simplicity through automated ejection and rebound detection systems

Inventive Principle:

Principle #15Dynamics

3Measurement precision

If optical sensors are used to measure impact speed and rebound speed, then the coefficient of restitution can be calculated accurately, but the device complexity increases compared to conventional hardness testers

Engineering Contradiction:

Improvespeed measurement accuracyVSAvoidapparatus structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The invention replaces complex mechanical speed measurement mechanisms with optical sensors that use light to detect and measure the impact speed and rebound speed of the indenter. This substitution provides accurate speed measurements while maintaining relative simplicity in the overall apparatus structure, as optical sensors eliminate the need for complex mechanical linkages and moving parts

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables accurate measurement of hardness by minimizing the mass effect and allowing tests to be performed in any direction, improving the precision and versatility of hardness testing for small and light specimens.

Implementation Method 1

speed measuring unit using optical sensors to calculate the coefficient of restitution

Methodology Applied

Scientific EffectOptical detection: Photoelectric Effect

Implementation Method 2

ejection mechanism configured to eject the indenter held by the holder from the holder to a specimen

Methodology Applied

Scientific EffectMechanical ejection: Spring

Implementation Method 3

coefficient of restitution that is a ratio of the rebound speed to the impact speed

Methodology Applied

Scientific EffectElastic rebound: Elasticity

Data Source

PatentEP3165897B1Apparatus for measuring coefficient of restitution and hardness tester

Publication Date: 2023.07.19 YAMAMOTO SCI TOOL LAB CO LTD

Figure 1
Figure 2A~2B
Figure 3

AI summary

An apparatus for measuring for measuring coefficient of restitution which is capable of reducing a mass effect and performing tests in free directions, is disclosed. The apparatus for measuring coefficient of restitution includes a holder for holding a spherical indenter, an ejection mechanism configured to eject the indenter held by the holder from the holder to a specimen, a speed measuring unit configured to measure an impact speed that is a speed of the indenter before the indenter impacts against the specimen, and a rebound speed that is a speed of the indenter after the indenter is rebounded from the specimen; and an arithmetic unit configured to calculate a coefficient of restitution that is a ratio of the rebound speed to the impact speed.