Slit Grommet Structure for Easy Cover Attachment and Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing grommets for attaching soundproof covers to engines require poor adhesive properties between rubber and urethane, leading to increased costs and man-hours, and when made of resin, they are difficult to attach and detach due to high force requirements, which can damage the grommet.
Innovation Solution
A grommet with a concave part and pull-out prevention part, featuring slits and ribs, is formed integrally with the cover, allowing for easier attachment and detachment by elastic deformation and reducing the need for adhesion processing, while maintaining a high adhesive property with urethane covers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the grommet is formed of rubber, then adhesion between rubber and urethane is poor requiring adhesion processing, but using resin eliminates adhesion processing and reduces weight
Solution Approach 1:
The patent changes the material parameter from rubber to resin (specifically polypropylene or similar), which fundamentally alters the adhesion characteristics. The resin material inherently bonds well with urethane covers without requiring additional adhesion processing, while simultaneously reducing weight compared to rubber materials.
Solution Approach 2:
The grommet is formed as a composite structure integrating the resin material with the urethane cover. This composite approach allows the resin grommet to maintain structural integrity while providing sufficient bonding strength to the urethane cover without requiring separate adhesion layers or processing steps.
2Loss of substance
If the grommet is formed of resin, then adhesion processing is not required and weight is reduced, but a large amount of force is required to fit or remove the attachment pin which may damage the grommet
Solution Approach 1:
The grommet is segmented into multiple functional zones: a fitting portion with a smaller inner diameter for secure attachment pin insertion, and an open end portion with a larger inner diameter for easy attachment/detachment operations. This segmentation allows the attachment pin to be firmly held during operation while enabling simple removal when needed.
Solution Approach 2:
Different portions of the grommet have different dimensional qualities - the fitting portion has a smaller inner diameter (equal to or smaller than the attachment pin outer diameter) for secure holding, while the open end portion has a larger inner diameter for ease of operation. This local quality variation resolves the contradiction between secure attachment and easy detachment.
3Ease of operation
If the grommet is formed of rubber, then workability for attachment/detachment is good, but adhesion processing is required increasing cost and man-hours
Solution Approach 1:
The patent changes the material parameter from rubber to resin, which fundamentally alters the adhesion characteristics. The resin material inherently bonds well with urethane covers without requiring additional adhesion processing, eliminating the time-consuming primer application steps while maintaining good workability for attachment and detachment.
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 design improves workability for attachment and detachment, reduces weight and cost, and ensures secure fitting and removal of the cover without damaging the grommet, enhancing the overall mounting process.
Implementation Method 1
a plurality of slits formed in a fitting direction of the attachment pin from the open end portion and disposed at predetermined interval in a circumferential direction of the concave part
Implementation Method 2
a pull-out prevention part buried in the attachment part and configured to prevent pulling out from the attachment part, wherein the pull-out prevention part includes a plurality of first ribs disposed on extension lines of the slits
Data Source
AI summary
The concave part includes an open end portion having an inner diameter greater than an outer diameter of a tip end portion of a ball stud, a fitting portion which is connected to the open end portion and has an inlet smaller than the outer diameter of the tip end portion and in which the tip end portion is housed, and a plurality of slits which are formed in a fitting direction of the ball stud from the open end portion and arranged at a predetermined interval along the circumference of the concave part. The pull-out prevention part includes a plurality of first ribs located on extensions of the respective slits.