Fuel Hose Routing Between Throttle Cables in Straddled Vehicle

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Solution Overview

Problem

In straddled vehicles, the proximity of the injector to the throttle drum can cause interference between the fuel hose and throttle cables, leading to potential bending issues and increased load on the fuel hose, which complicates the arrangement and increases costs.

Innovation Solution

The fuel hose is configured to pass between the first and second throttle cables, eliminating the need for sharp bends and allowing the injector to be positioned closer to the throttle drum, using a resin hose for increased rigidity and reduced costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the injector is disposed relatively close to the throttle drum, then the device complexity is reduced and space is saved, but the fuel hose and throttle cables interfere with each other

Engineering Contradiction:
Improvearrangement complexityVSAvoidinterference between fuel hose and throttle cables
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The fuel hose routing transitions from a planar arrangement (above or below the cables) to a three-dimensional configuration by passing the fuel hose through a cavity or passage in the throttle drum body. This dimensional change allows the fuel hose to occupy space between the cables without interfering with either, enabling compact injector positioning while eliminating interference.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If the fuel hose is extended to pass above or below the throttle cables, then interference is avoided, but the fuel hose is bent sharply causing increased load

Engineering Contradiction:
Improveinterference between fuel hose and throttle cablesVSAvoidload on fuel hose
Core Design Contradiction:
Object-affected harmful factorsVSForce

Solution Approach 1:

The fuel hose is routed through a cavity or passage within the throttle drum body, nesting the hose inside the structural volume of the drum. This eliminates the need for external sharp bends and allows the hose to follow a gradual, protected path from the injector to the throttle cable connection point, reducing mechanical stress and load on the hose.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of manufacture

If a resin fuel hose is used, then costs are reduced and rigidity is increased, but the hose is more susceptible to load at connection portions and bent portions

Engineering Contradiction:
Improvefuel hose costVSAvoidfuel hose load resistance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The throttle drum structure is designed in advance to include a dedicated cavity or passage for the fuel hose, and the hose is pre-routed through this protected pathway. This preliminary structural preparation ensures that when the resin hose is installed, it follows a predetermined load-distributing path that avoids concentration of stress at connection points or sharp bends, thereby maintaining hose strength while using cost-effective resin material.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4212716B1Straddled vehicle
Publication Date: 2024.10.16 YAMAHA MOTOR CO LTD
  • EP4212716B1 patent drawingFigure 1
  • EP4212716B1 patent drawingFigure 2
  • EP4212716B1 patent drawingFigure 3

AI summary

A motorcycle 1 includes: an injector 60 attached to an internal combustion engine 4; an intake passage 38 connected to the internal combustion engine 4; a throttle valve 40 disposed in the intake passage 38; a throttle drum 42 connected to the throttle valve 40, a first throttle cable 51 and a second throttle cable 52 connected to the throttle drum 42; and a fuel hose 70 connected to the injector 60. The fuel hose 70 has an intersection portion 75 passing between the first throttle cable 51 and the second throttle cable 52.