Fuel Injection Valve Mounting Structure Using Internal Positioning
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Solution Overview
Problem
The existing fuel injection valve mounting structures have positioning means that project outward, leading to a larger size and less favorable appearance due to the need for thick projections to enhance strength, which is not ideal for fuel supply caps.
Innovation Solution
A fuel injection valve mounting structure with a synthetic resin covering body around the fuel injection valve, featuring semicircular shoulder parts and a standing wall, combined with a rotation stopper surface on the fuel supply cap, restricts the coupler's orientation without external projections, enhancing strength and reducing size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sandwiching pieces are formed on the fuel supply cap to create positioning means, then the orientation of the coupler can be restricted, but the sandwiching pieces project outward leading to larger size and less favorable appearance
Solution Approach 1:
The positioning structure is nested within the fuel supply cap body. The positioning protrusions are formed as integral parts of the cap's internal structure rather than external projections, allowing the positioning function to be embedded within the existing form factor of the fuel supply cap.
Solution Approach 2:
The positioning mechanism transitions from external radial projections to internal axial features. The positioning protrusions extend axially inward from the front end of the fuel supply cap, utilizing the axial dimension rather than radial projections, thereby maintaining a compact external profile while providing effective positioning.
2Strength
If sandwiching pieces are thickly formed to enhance the strength of the positioning means, then the positioning strength is improved, but the surrounding of the fuel supply cap becomes large-sized
Solution Approach 1:
The positioning strength is achieved through multiple discrete positioning protrusions distributed around the circumference of the fuel supply cap. Each protrusion can be relatively thin, but the collective effect of multiple protrusions provides sufficient positioning strength while maintaining a compact overall volume.
Solution Approach 2:
The positioning protrusions are formed as integral parts of the fuel supply cap, utilizing the same material throughout. This integrated construction allows for optimized material distribution where material is concentrated at the positioning features while the overall cap volume remains minimized.
3Ease of operation
If positioning means restricts the orientation of the coupler, then the coupler orientation is controlled, but the positioning means projects outward deteriorating the appearance
Solution Approach 1:
The positioning function is extracted from the external surface of the fuel supply cap and relocated to internal features. The positioning protrusions are formed on the internal circumference and front end face, removing the need for external projections that would compromise the aesthetic appearance.
Solution Approach 2:
The positioning protrusions act as intermediary features between the fuel supply cap and the coupler. These protrusions engage with corresponding recesses or surfaces on the coupler to provide orientation control, while remaining hidden within the overall assembly and not affecting the external appearance of the fuel supply cap.
Data Source
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AI summary
A covering body (10) made of a synthetic resin and including a rear shoulder part (16) oriented toward a fuel inlet part (6) side is formed around an outer periphery of an intermediate portion in an axial direction of a fuel injection valve (I). The rear shoulder part (16) includes: a first semicircular shoulder part (16a) extending over a half periphery of the covering body (10); a second semicircular shoulder part (16b) shifted in the axial direction with respect to the first semicircular shoulder part (16a) and extending over the other half periphery of the covering body (10); and a standing wall (16c) standing to connect the first and second semicircular shoulder parts (16a, 16b). On a front end of a fuel supply cap (20), a semicircular holding surface (28b) holding at least one of the first and second semicircular shoulder parts (16a, 16b) to prevent the fuel injection valve (I) from being fallen off from the mounting hole (2), and a rotation stopper surface (28c) abutting against the standing wall (16c) to prevent rotation of the fuel injection valve (I) are formed. Accordingly, it is possible to provide a fuel injection valve mounting structure including positioning means capable of firmly restricting an orientation of a coupler in a given direction without forming projections on a fuel injection valve and a fuel supply cap.