Spool Flange Through Hole Positioning for Noise Reduction

Solution Overview

Problem

Dual-bearing reels with through holes in the flanges produce noise during high-speed rotation due to air passing through, compromising the reduction in mass and inertia achieved by these designs.

Innovation Solution

The spool design features a bobbin trunk with a tubular shape and circular flanges, where the first through holes are positioned radially inward at a distance less than or equal to 60% of the difference between the bobbin trunk and flange diameters, covered by the fishing line during initial casting, preventing air from passing through and reducing noise. Additionally, the holes can be circular or elongated with rounded ends, and the flanges have a gradually increasing thickness and chamfered edges to further inhibit noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If through holes are provided in the flanges to reduce mass and inertia, then the spool can be reduced in mass and inertia without reducing its outer diameter, but noise is produced during high-speed rotation due to air passing through the through holes

Engineering Contradiction:

Improvemass of spoolVSAvoidnoise during high-speed rotation

Core Design Contradiction:

Weight of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by positioning the through holes at specific radial distances from the outer peripheral surface of the bobbin trunk. The holes are located at a distance greater than 0% and less than or equal to 60% of the radial distance, creating a localized arrangement that allows air passage control while maintaining weight reduction benefits in specific areas of the flange structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements preliminary action by pre-positioning the through holes at optimized radial distances before the spool operates. This preliminary arrangement ensures that during high-speed rotation, the holes are strategically located to minimize air turbulence and noise generation while still achieving the mass reduction objective.

Inventive Principle:

Principle #10Preliminary action

2Weight of moving object

If through holes are provided in the flanges to reduce mass and inertia, then the spool can be reduced in mass and inertia without reducing its outer diameter, but air passes through the through holes causing wind noise

Engineering Contradiction:

Improveinertia of spoolVSAvoidwind noise

Core Design Contradiction:

Weight of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by positioning the through holes at specific radial distances from the outer peripheral surface of the bobbin trunk. The holes are located at a distance greater than 0% and less than or equal to 60% of the radial distance, creating a localized arrangement that allows air passage control while maintaining weight reduction benefits in specific areas of the flange structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements preliminary action by pre-positioning the through holes at optimized radial distances before the spool operates. This preliminary arrangement ensures that during high-speed rotation, the holes are strategically located to minimize air turbulence and noise generation while still achieving the mass reduction objective.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If the through holes are positioned closer to the outer peripheral surface of the bobbin trunk, then easier machining or molding is achieved, but air flow through the holes increases causing more noise

Engineering Contradiction:

Improvemachining or molding of through holesVSAvoidnoise from air passage

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by optimizing the radial position parameter of the through holes. The specific parameter range (greater than 0% and less than or equal to 60% of the radial distance from the outer peripheral surface) balances the competing requirements of manufacturability and noise reduction, representing an optimized parameter selection that satisfies both ease of manufacture and noise control.

Inventive Principle:

Principle #35Parameter changes

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 effectively inhibits noise production during high-speed rotation while maintaining reduced mass and inertia, ensuring the spool operates quietly and efficiently.

Implementation Method 1

the first through holes are covered with the fishing line and are not exposed to the outside in an initial phase of casting in which the speed of casting is the fastest. Therefore, air is prevented from passing through the first through holes

Methodology Applied

Scientific EffectPhysical barrier (fishing line coverage):

Data Source

PatentUS10182563B2Spool for dual-bearing reel

Publication Date: 2019.01.22 SHIMANO INC

AI summary

A spool for a dual-bearing reel includes a bobbin trunk having a tubular shape, a pair of flanges and a plurality of first through holes. Each flange is provided on opposite ends of the bobbin trunk, each flange having a circular shape and a larger diameter than the bobbin trunk. The first through holes are provided in at least one flange of the pair of flanges and are circumferentially disposed at intervals about the at least one flange. The first through holes open in a radial position located at a distance away from an outer peripheral surface of the bobbin trunk, the distance being less than or equal to a second distance from the outer peripheral surface of the bobbin trunk, the second distance being 60% of a distance from the outer peripheral surface of the bobbin trunk to an outer peripheral surface of the at least one flange.