Fuel Tank Arrangement Under Saddle Vehicle Step Floor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional scooter-type motorcycles with a fuel tank under the step floor face limitations in lowering the step floor due to potential load application on the fuel pump, which requires additional structural protection, potentially heightening the step floor position.
Innovation Solution
The fuel tank is positioned between frame members extending under the step floor, with an inclined fuel pump and flange face configuration that keeps the fuel pump's upper end below the frame members, allowing for a lower step floor while maintaining structural integrity and increasing fuel tank capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the fuel tank is disposed under the step floor with the fuel pump protruding above, then the fuel pump can be easily accessed and installed, but the step floor cannot be lowered sufficiently due to load protection requirements
Solution Approach 1:
The fuel pump body is inclined relative to the vertical direction, changing its orientation from the conventional vertical alignment to an angled configuration. This dimensional change allows the pump to be positioned efficiently within the constrained space under the step floor while maintaining accessibility, resolving the contradiction between pump accessibility and step floor height.
Solution Approach 2:
The fuel pump is nested within the space defined by the frame members, with its upper end positioned below the upper face of the frame members. This nesting approach allows the pump to be accommodated within the existing structural envelope without requiring additional clearance that would prevent step floor lowering.
2Stability of the object's composition
If the step floor is lowered to improve riding performance, then weight distribution improves, but the fuel pump may be subjected to excessive load requiring additional protection structures
Solution Approach 1:
The frame members serve as an intermediary protective structure between the step floor and the fuel pump. The upper ends of the frame members extend above the upper end of the fuel pump, creating a protective envelope that shields the pump from direct load applied by the step floor, thus eliminating the need for additional protection structures.
Solution Approach 2:
The frame members are positioned and dimensioned in advance to provide protective coverage over the fuel pump before any load is applied. The configuration ensures that the frame members' upper faces are above the fuel pump's upper end, creating a pre-established protective barrier that cushions the pump against potential loads.
3Ease of manufacture
If the fuel pump is positioned vertically for easy installation, then manufacturing and assembly are simplified, but the step floor height must be increased to accommodate the pump
Solution Approach 1:
The fuel pump body is configured with asymmetric orientation, inclined at an angle relative to the vertical direction rather than being perfectly vertical. This asymmetric positioning allows the pump to fit within the available space under the step floor while maintaining ease of installation, breaking the conventional symmetric vertical alignment requirement.
Solution Approach 2:
The orientation parameter of the fuel pump is changed from vertical (0 degrees) to an inclined angle. This parameter change allows the pump to be positioned within the constrained vertical space while maintaining accessibility for installation and maintenance, effectively reducing the required step floor height.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a motorcycle capable of lowering the step floor while placing a fuel tank under the step floor. A motorcycle includes: a step floor (11) between a steering handle (5) and a seat (13); and a fuel tank (70) disposed under the step floor (11) and between a pair of frame members (34) extending in the front-rear direction of the vehicle body. The fuel tank (70) has an opening (74) at an upper part to insert a body (92) of a fuel pump (90). The upper end (91) of the fuel pump (90) is fixed to a peripheral part (75) of the opening (74). The upper end (91) of the fuel pump (90) is located below the upper faces (34a) of the frame members (34) in side view of the vehicle body. The fuel tank (70) includes an upper half body (UC) and a lower half body (DC) that are bonded at a flange face (G). The flange face (G) intersects the axial line (C) of the frame members (34) in side view of the vehicle body.