Vertical Fuel Tank for Mass Centralization in Straddled Vehicles

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Solution Overview

Problem

Conventional straddled vehicles face challenges in centralizing mass while maintaining fuel tank capacity and passenger comfort, as moving the main and tandem seats forward to centralize mass can reduce fuel tank capacity and passenger riding space.

Innovation Solution

The fuel tank is positioned behind the head pipe and above the engine, with an upper edge portion and a lower edge portion, and a first inclined portion that extends forward and upward, allowing the main and tandem seats to be moved forward while maintaining fuel tank capacity and encouraging the rider to adopt a posture that enhances passenger contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the main seat and tandem seat are moved forward to centralize mass, then mass centralization is improved, but the fuel tank capacity decreases and passenger riding space becomes narrow

Engineering Contradiction:
Improvemass centralizationVSAvoidfuel tank capacity
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The fuel tank is repositioned from a horizontal arrangement to a vertical arrangement above the engine. By extending the fuel tank in the up-down direction rather than the front-rear direction, the patent achieves mass centralization while maintaining fuel capacity. The vertical placement allows the fuel tank to occupy space above the engine without encroaching on the riding space or requiring the seats to be positioned further back.

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

2Stability of the object's composition

If the main seat and tandem seat are moved forward to centralize mass, then mass centralization is improved, but passenger comfort degrades due to reduced riding space

Engineering Contradiction:
Improvemass centralizationVSAvoidpassenger comfort
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The fuel tank is repositioned from a horizontal arrangement to a vertical arrangement above the engine. By extending the fuel tank in the up-down direction rather than the front-rear direction, the patent achieves mass centralization while maintaining fuel capacity. The vertical placement allows the fuel tank to occupy space above the engine without encroaching on the riding space or requiring the seats to be positioned further back.

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

3Quantity of substance

If the fuel tank is made long in the front-rear direction to maintain capacity while moving seats forward, then fuel tank capacity is maintained, but the center of gravity of the fuel tank moves upward and away from the engine

Engineering Contradiction:
Improvefuel tank capacityVSAvoidmass centralization
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The fuel tank is repositioned from a horizontal arrangement to a vertical arrangement above the engine. By extending the fuel tank in the up-down direction rather than the front-rear direction, the patent achieves mass centralization while maintaining fuel capacity. The vertical placement allows the fuel tank to occupy space above the engine without encroaching on the riding space or requiring the seats to be positioned further back.

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

Solution Approach 2:

The patent changes the dimensional parameters of the fuel tank by making it taller in the up-down direction rather than longer in the front-rear direction. This parameter change allows the fuel tank to maintain its capacity while being positioned closer to the engine in the front-rear direction, thereby achieving mass centralization.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If the air cleaner is disposed above the engine, then engine access is improved, but the fuel tank cannot be positioned as close to the engine as possible

Engineering Contradiction:
Improveengine accessVSAvoidmass centralization
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The fuel tank is repositioned from a horizontal arrangement to a vertical arrangement above the engine. By extending the fuel tank in the up-down direction rather than the front-rear direction, the patent achieves mass centralization while maintaining fuel capacity. The vertical placement allows the fuel tank to occupy space above the engine without encroaching on the riding space or requiring the seats to be positioned further back.

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

Data Source

PatentEP3115291B1Straddled vehicle
Publication Date: 2020.12.09 YAMAHA MOTOR CO LTD
  • EP3115291B1 patent drawingFigure 1
  • EP3115291B1 patent drawingFigure 2
  • EP3115291B1 patent drawingFigure 3

AI summary

A dimension (X1) in a vehicle up-down direction from an upper edge portion (81) of a fuel tank (35) to a lower edge portion (85) of the fuel tank (35) is greater than a dimension (X2) of the upper edge portion (81) of the fuel tank (35) in a vehicle front-rear direction. In a plan view, at least a portion of a front edge of a main seat (23) is disposed behind a rear edge portion (83) of the fuel tank (35). In a side view, a rear end of the fuel tank (35) and a front end (23f) of the main seat (23) are disposed further to the front than a pivot axis. In the side view, a center of a tandem seat in the vehicle front-rear direction is disposed further to the front than a rotation center of a rear wheel.