Noncircular Pin Clip With Guide Ramp for Misalignment

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Solution Overview

Problem

The existing clip designs with noncircular pins and grommets face inefficiencies in temporary fixing due to misalignment and displacement issues during automatic assembly, leading to potential damage and reduced work efficiency.

Innovation Solution

Incorporating a ramp at the entrance of the grommet's insertion hole that guides the pin into position, allowing for rotational alignment and temporary fixing, even when the pin is slightly displaced, thereby simplifying the insertion process and reducing the risk of damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a noncircular pin is inserted into a grommet with slits for temporary fixing, then the pin can be positioned and fixed, but misalignment or displacement occurs during automatic assembly, preventing proper fixing or causing damage

Engineering Contradiction:
Improveinsertion position accuracyVSAvoidmanual insertability
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

A guide pin is introduced as an intermediary component to facilitate the insertion of the main pin into the grommet. The guide pin has a smaller diameter than the main pin and fits into a guide hole in the grommet, providing alignment guidance. This intermediary structure enables automatic assembly machines to easily align and insert the pin without complex positioning mechanisms, while ensuring precise insertion position.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pin insertion function is segmented into two parts: a guide pin for alignment and positioning, and the main pin for the actual fixing function. The guide pin handles the alignment task separately, allowing the main pin to focus on the fixing function. This segmentation resolves the contradiction by separating the positioning requirement from the fixing requirement, enabling both precision and ease of operation.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the pin and grommet are designed for automatic assembly, then work efficiency improves, but misalignment prevents temporary fixing or damages components

Engineering Contradiction:
Improveassembly efficiencyVSAvoidtemporary fixing reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The guide pin structure serves as a cushioning mechanism that prevents misalignment damage before it occurs. By providing a preliminary alignment path through the guide hole, the system cushions against potential misalignment issues that would otherwise cause assembly failures or component damage, ensuring reliable temporary fixing during automatic assembly operations.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The guide pin acts as a mediator between the automatic assembly machine and the main pin-grommet assembly. It absorbs the alignment tolerance issues and provides a reliable positioning reference, enabling the automatic assembly machine to operate efficiently without compromising the reliability of the temporary fixing operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If position adjustment is performed by robot hand, then insertion accuracy improves, but the process becomes more complex and time-consuming

Engineering Contradiction:
Improveposition adjustment accuracyVSAvoidassembly process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The guide pin structure enables the pin-grommet assembly to self-align during insertion. The guide hole and guide pin geometry automatically guide the main pin into the correct position without requiring external robot hand adjustment. This self-service alignment mechanism eliminates complex positioning devices and reduces assembly process complexity while maintaining high insertion accuracy.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2309140B1clip
Publication Date: 2015.10.14 NIFCO INC
  • EP2309140B1 patent drawingFigure 1(a)~1(b)
  • EP2309140B1 patent drawingFigure 2(a)~2(b)
  • EP2309140B1 patent drawingFigure 3(a)~3(b)

AI summary

A clip includes a pin having at at least a part thereof a noncircular cross-section, and a grommet having an insertion hole into which the pin can be inserted, wherein a part of the grommet is adapted to be expandable by insertion of the pin into the insertion hole. The grommet has slope surfaces provided at an entrance-side hole edge of the insertion hole to lead the pin into the insertion hole when the pin is displaced from a normal position to be in contact with the entrance-side hole edge of the insertion hole.