Motorcycle Muffler Centering for Increased Bank Angle
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Solution Overview
Problem
In motorcycles with a unit swing type engine unit, the arrangement of a rear suspension and brake caliper between the swing arm and muffler causes the muffler to project outward, reducing the bank angle.
Innovation Solution
The motorcycle design positions the brake caliper below the muffler and the suspension unit above it, with the muffler mounted on the swing arm, allowing the muffler to be centered and reducing interference, thus increasing the bank angle and minimizing heat influence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the rear suspension and brake caliper are arranged between the swing arm and muffler, then the components can be accommodated in the available space, but the muffler projects outside the vehicle and the bank angle is decreased
Solution Approach 1:
The patent transitions from a horizontal arrangement of components (suspension and brake caliper between swing arm and muffler) to a vertical stacking arrangement (suspension above muffler, brake caliper below muffler). This dimensional change allows the muffler to be positioned closer to the vehicle centerline, increasing the bank angle while still accommodating all necessary components.
2Shape
If the muffler is positioned to increase bank angle, then the vehicle's leaning capability is improved, but the muffler may interfere with the brake caliper and suspension
Solution Approach 1:
By arranging the brake caliper and suspension in the vertical dimension (above and below the muffler respectively) rather than horizontally, the patent eliminates lateral interference between these components while still achieving a increased bank angle.
Solution Approach 2:
The patent positions the brake caliper and suspension in a nested arrangement around the muffler in the vertical dimension, with the muffler centered and the other components stacked above and below it, allowing compact integration without interference.
3Ease of operation
If the muffler projects outside the vehicle, then the components can be arranged in the conventional manner, but the bank angle is decreased
Solution Approach 1:
The patent uses vertical stacking to accommodate components that would traditionally be arranged horizontally, allowing the muffler to be repositioned inward toward the vehicle centerline, thereby increasing bank angle while maintaining ease of component installation.
Data Source
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AI summary
A motorcycle 1 comprises a body frame 2, an engine unit 8 pivotally mounted on the body frame about a pivot shaft 51 and arranged to swing vertically relative to the body frame 2, and a rear wheel 7 mounted on the engine unit 8. The motorcycle 1 also comprises a suspension unit 10 disposed between the engine unit 8 and the body frame 2, and a brake caliper 57 for the rear wheel 7. Furthermore, a muffler 80 is provided and is secured relative to the engine unit 8 such that the suspension unit 10 is positioned above the muffler 80 and the brake caliper 57 is positioned below the muffler 80.