Asymmetric Straddle-Type Vehicle Frame Stiffness
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Solution Overview
Problem
The vehicle body frame structure of straddle-type vehicles requires a balance between sufficient strength to support the rear wheel and reduced weight for improved mobility, with existing designs struggling to achieve this balance effectively.
Innovation Solution
A vehicle body frame structure is designed with a driving power transmission mechanism placed on one side, featuring main frames with varying stiffness and pipe members connected by welding, allowing for flexible design and weight reduction without compromising strength, including trellis frame configurations and different thicknesses to manage reactive forces and load distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the stiffness of the main frame is increased to support the driving power transmission mechanism and receive reactive forces, then the strength and stability are improved, but the weight of the vehicle body frame increases
Solution Approach 1:
The patent applies different stiffness levels to different sides of the main frame. The first side main frame has higher stiffness to receive reactive forces from the driving power transmission mechanism, while the second side main frame has lower stiffness to reduce weight. This local differentiation of structural properties allows the frame to be strong where needed and lightweight where not required, resolving the contradiction between strength and weight.
2Weight of moving object
If the main frame structure is made asymmetric with different stiffness on each side, then the weight is reduced and design flexibility is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent deliberately creates an asymmetric main frame structure where the first side and second side have different stiffness characteristics. The first side main frame includes reinforcement structures or thicker sections to handle reactive forces, while the second side uses lighter construction. This asymmetric design reduces overall weight and provides design flexibility for accommodating the driving power transmission mechanism on one side, while the added manufacturing complexity is offset by the performance benefits.
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 enables a reduction in weight while maintaining strength, allowing for improved mobility and stability by optimizing the stiffness and load transfer within the frame structure.
Implementation Method 1
a plurality of pipe members connecting the joint members to each other by welding
Data Source
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AI summary
A vehicle body frame structure is applied to a straddle-type vehicle (100) in which a driving power transmission mechanism (104) which transmits rotational power of a driving source (103) to a rear wheel (102) is placed on a first side in a vehicle width direction, with respect to a center line of a vehicle body in the vehicle width direction. The vehicle body frame structure comprises a head pipe (2); and a pair of main frames (3 (3R, 3L)) extending rearward and outward in the vehicle width direction from the head pipe (2) in such a manner that the main frames (3(3R, 3L)) are spaced apart from each other in the vehicle width direction. The pair of main frames (3(3R, 3L) include portions (45R, 45L), respectively, facing the driving power transmission mechanism (104) in the vehicle width direction, and the portion (45R) facing the driving power transmission mechanism and being located on a second side in the vehicle width direction has a stiffness lower than that of the portion (45L) facing the driving power transmission mechanism and being located on the first side in the vehicle width direction.