Saddle Riding Vehicle Frame Cross Member Using Composite Materials

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Solution Overview

Problem

The existing vehicle body frame structures for saddle riding vehicles face challenges in maintaining steering performance by suppressing deformation of upper edge portions of main frames while ensuring sufficient space for member disposition between them, as cross members interfere with components like air cleaners and electrical components.

Innovation Solution

A vehicle body frame structure featuring a cross member made of a material with higher specific rigidity than the metal main frames, such as carbon fiber reinforced resin, which is oriented uniformly in the vehicle body width direction, reducing the cross section and preventing deformation of the main frames, allowing for increased rigidity and member disposition space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the cross member is disposed on the upper edge portions of the left and right main frames to suppress deformation, then steering performance is improved, but the cross member interferes with members disposed between the main frames such as air cleaners and electrical components

Engineering Contradiction:
Improverigidity of upper edge portions of main framesVSAvoidmember disposition space between main frames
Core Design Contradiction:
StrengthVSArea of stationary object

Solution Approach 1:

The cross member is formed of a material having higher specific rigidity than the metal material constituting the main frames, such as carbon fiber reinforced resin. This allows the cross member to achieve the required rigidity with a smaller cross section, thereby preventing deformation of the main frames while securing sufficient member disposition space between the frames.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

By changing the material parameter (specific rigidity) of the cross member from conventional metal to high-specific-rigidity material like carbon fiber reinforced resin, the cross section of the cross member can be reduced while maintaining or improving its rigidity function, thus resolving the space interference issue.

Inventive Principle:
Principle #35Parameter changes

2Strength

If a cross member with sufficient rigidity is used to prevent deformation of main frames, then steering performance is improved, but the cross section of the cross member increases reducing member disposition space

Engineering Contradiction:
Improverigidity of cross memberVSAvoidmember disposition space between main frames
Core Design Contradiction:
StrengthVSArea of stationary object

Solution Approach 1:

The cross member is formed of a material having higher specific rigidity than the metal material constituting the main frames, such as carbon fiber reinforced resin. This allows the cross member to achieve the required rigidity with a smaller cross section, thereby preventing deformation of the main frames while securing sufficient member disposition space between the frames.

Inventive Principle:
Principle #40Composite materials

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 configuration enhances steering performance by preventing deformation of the main frames and securing sufficient space for components, while reducing manufacturing costs through optimized carbon fiber usage and eliminating the need for gaps between integrated members.

Implementation Method 1

the material having a high specific rigidity that constitutes the cross member may be configured linearly by a carbon fiber reinforced resin in which carbon fibers are oriented uniformly in a vehicle body width direction. In this case, tensile rigidity of the cross member in the vehicle width direction is increased by the linear carbon fiber reinforced resin.

Methodology Applied
Scientific EffectCarbon fiber reinforcement: Composite Materials

Data Source

PatentEP3366559B1Vehicle body frame structure for saddle riding vehicle
Publication Date: 2019.11.20 HONDA MOTOR CO LTD
  • EP3366559B1 patent drawingFigure 1
  • EP3366559B1 patent drawingFigure 2
  • EP3366559B1 patent drawingFigure 3

AI summary

A vehicle body frame includes a head section (11) that rotatably supports a steering shaft, a pair of left and right main frames (12L, 12R) extending from the head section (11) toward a rear side of a vehicle body, and a cross member (40) that connects the pair of left and right main frames (12L, 12R). Each of the main frames (12L, 12R) is formed of a metal material, and the cross member (40) is formed of a material having a higher specific rigidity than the metal material that constitutes each of the main frames (12L, 12R).