Limiting Cap Inversion for Needle Valve Assembly
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Solution Overview
Problem
Existing limiting caps for carburetors are difficult to assemble onto needle valves due to the positioning of the fixing and engagement parts, making it challenging to restrict the rotation of the needle valve effectively.
Innovation Solution
A limiting cap design with a main body featuring a first hubbly part on the inner peripheral surface engaging with a second hubbly part on the needle valve, and a rising part that restricts rotation by being inserted into a recess, with the fixing part having a smaller inner diameter than the engagement part, allowing for easier assembly and positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fixing part is formed to have a larger diameter than the engagement part with the engagement part on the outer side, then the limiting cap can effectively restrict rotation of the needle valve, but it becomes difficult to assemble the limiting cap onto the needle valve
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the fixing part on the outer side with a larger diameter and the engagement part on the inner side with a smaller diameter. This inversion allows the larger fixing part to be easily assembled first, while the smaller engagement part effectively restricts rotation of the needle valve.
2Stability of the object's composition
If the fixing part is located away from the operator at the time of fixing operation, then the limiting cap can maintain structural stability, but it becomes difficult to assemble the limiting cap onto the needle valve
Solution Approach 1:
The patent reverses the positional arrangement of parts, placing the fixing part on the outer side within easy reach of the operator, and the engagement part on the inner side. This inversion simultaneously improves assembly ease and maintains structural stability.
Solution Approach 2:
The patent utilizes the radial dimension of the cylindrical structure to differentiate part positions, with the fixing part on the outer radius and the engagement part on the inner radius. This dimensional arrangement allows both assembly ease and structural stability to be achieved.
3Reliability
If the engagement part is formed on the outer side and the fixing part on the inner side, then the limiting cap can restrict rotation effectively, but the operator cannot easily position and assemble the limiting cap
Solution Approach 1:
The patent inverts the conventional design by placing the fixing part on the outer side and the engagement part on the inner side. This inversion makes the assembly process easier while maintaining effective rotation restriction through the engagement part's positioning.
Data Source
AI summary
A limiting cap is provided to restrict rotation of a needle valve and to be easily assembled onto the needle cap. The limiting cap assembled onto the needle valve screwed into an adjustment hole of a fuel adjuster includes a main body to be arranged onto the needle valve. A rising part, which is inserted into a recess of the fuel adjuster, is formed on an outer peripheral surface of the main body. The main body includes a first engagement part on an inner side and a fixing part on an outer side. A first hubbly part formed in an inner peripheral surface of the first engagement part is engageable with a second hubbly part formed in an outer peripheral surface of the needle valve. The needle valve is fixed into the fixing part. The fixing part is formed to have a smaller inner diameter than the first engagement part.