Handheld Spring-Loaded Plunger for Projection Weld Impact Testing

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Solution Overview

Problem

Current methods for testing the quality of projection welded fasteners, such as push-out, torque, and impact tests, are either destructive, prone to false results, or lack accuracy due to variable force application.

Innovation Solution

A handheld quality inspection tool that applies a normative impact stroke using a plunger connected to a spring member, allowing for a controlled and consistent force application to projection welded components, improving reliability and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a manual impact test is performed by a tester using a hammer, then the test can be performed portably and quickly, but the accuracy and reliability are difficult to determine due to variable force application

Engineering Contradiction:

Improveportability and speed of testingVSAvoidaccuracy and reliability of impact force

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the manual hammering mechanism with a spring-loaded plunger system. The spring member stores mechanical energy when compressed by the plunger, and releases it to deliver a consistent impact force to the fastener. This substitution eliminates the variability of human force application while maintaining portability and ease of operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the parameter of impact force from variable (manual hammering) to controlled and consistent (spring-loaded mechanism). By using a spring member with known spring constant and controlled compression distance, the impact force parameter becomes repeatable and reliable across multiple tests.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a push-out test is performed using hydraulic pressure, then the strength of the metallurgical bond can be tested, but the device complexity increases due to required hydraulic machinery and guiding structures

Engineering Contradiction:

Improvestrength testing capabilityVSAvoidhydraulic machinery and guiding structures

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential function of the push-out test (applying force to test bond strength) and removes the complex hydraulic machinery and guiding structures. The simplified device uses only a spring-loaded plunger to apply impact force directly to the fastener, eliminating unnecessary complexity while maintaining reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a simple, inexpensive spring-loaded mechanism instead of expensive hydraulic equipment. The device is designed to be portable and can be easily replaced or reset after each test, functioning as a disposable or single-use testing solution that eliminates the need for complex permanent installations.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If a torque test is performed with a torque wrench, then the fastener can be tested for bond strength, but false results occur when a specified torque approves an otherwise undersized weld

Engineering Contradiction:

Improvebond strength assessmentVSAvoidaccuracy of weld size verification

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent inverts the testing approach: instead of applying torque to see if the fastener holds (torque test), it applies impact force to see if the fastener remains bonded (impact test). This inversion reveals weld deficiencies that torque tests miss, as the impact force better simulates real-world thermal expansion and contraction stresses.

Inventive Principle:

Principle #13The other way round (Inversion)

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

Ensures accurate and reliable testing of projection welded components by providing a consistent impact force, reducing the risk of injury and enabling quick, portable testing of multiple components.

Implementation Method 1

The spring member is disposed within the elongated hollow tube and connected to the plunger and the spring support. The plunger is movable within the elongated hollow tube between a first position adjacent to the end flange and a second position adjacent to the spring support such that moving the plunger from the first position to the second position compresses the spring member.

Methodology Applied

Scientific EffectSpring: Spring

Data Source

PatentUS11740168B2Quality inspection tool for projection welded fasteners

Publication Date: 2023.08.29 VOLVO CAR CORP

AI summary

A handheld quality inspection tool for projection welded components and method for utilizing the same is disclosed. The handheld quality inspection tool includes an elongated hollow tube, a spring support, a spring member, a plunger, and a handle. The elongated hollow tube defines a slot. The spring support is connected to an end portion of the elongated tube. The spring member is disposed within the elongated hollow tube and connected to the spring support. The plunger is disposed in the elongated hollow tube and connected to the spring member opposite the spring support. The handle is connected to the plunger and protrudes from the elongated hollow tube through the slot and is translatable along the slot to move the plunger and compress the spring member. Upon release of the handle, the compressed spring member propels the plunger to apply an impact force to a projection welded component.