Fuel Injection Rack Linkage to Reduce Operating Shaft Wear
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Solution Overview
Problem
Traditional fuel injection devices suffer from excessive abrasion and deteriorated responsiveness due to a laterally offset arrangement of the control rack and link lever, which applies a large bending moment to the operating shaft, leading to reduced lifespan and performance.
Innovation Solution
The fuel injection device is redesigned with the actuator-side connecting part positioned on the operating shaft, incorporating a biasing member to bias the link lever, and a pair of lever members pivotally supported to apply load evenly along the operating shaft, reducing bending moments and abrasion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the control rack and link lever are arranged laterally offset from the actuator center, then the fuel pressure-feed amount can be adjusted, but a large bending moment is applied to the operating shaft causing excessive abrasion
Solution Approach 1:
The invention repositions the actuator laterally so that its operating shaft aligns with the link lever's swing axis, changing the spatial arrangement from a laterally offset configuration to a collinear configuration. This dimensional adjustment eliminates the bending moment by ensuring forces act along the same axis, thereby resolving the contradiction between maintaining adjustment capability and preventing shaft wear
2Reliability
If the actuator is positioned to align with the link lever swing axis, then bending moment on operating shaft is reduced, but device complexity increases due to additional connecting parts
Solution Approach 1:
The invention integrates the actuator-side connecting part directly into the operating shaft structure, merging the connecting function with the existing shaft component. This eliminates the need for separate connecting elements and reduces overall structural complexity while maintaining the aligned configuration that reduces bending moments
3Reliability
If the actuator-side connecting part is positioned on the operating shaft, then abrasion of sliding members is suppressed, but manufacturing precision requirements increase
Solution Approach 1:
The invention designs the actuator-side connecting part to automatically self-align with the link lever swing axis through geometric constraints and mating features. This self-aligning mechanism eliminates the need for high-precision manual positioning during assembly, allowing standard manufacturing tolerances to achieve the required alignment for minimizing bending moments
Data Source
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AI summary
A technology that can extend the life of a fuel injection device of an engine while maintaining its good responsiveness is provided. A fuel injection device 100 for an engine includes: a control rack 55 supported to be slidable in an axial direction and capable of adjusting of a fuel pressure-feed amount of a fuel pressure-feed mechanism unit 51, based on its slide-position relative to the axial direction; an actuator 40 capable of reciprocating its operating unit 41; and a link lever 20 swingably supported by a pivot shaft member 25 and configured to swing in association with reciprocation of the operating unit 41 of the actuator 40 thereby causing the control rack 55 to slide, wherein the fuel injection device includes an actuator-side connecting part 20A connecting an operating unit 41 of the actuator 40 to the link lever 20, and the actuator-side connecting part 20A is positioned on the same axis as the operating unit 41 of the actuator 40.