Fuel Injector Locating Pins Prevent Rotation
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Solution Overview
Problem
Existing fuel injectors in internal combustion engines face issues with rotational variability due to clearance fits, leading to suboptimal fuel spray placement and reduced fuel efficiency along with increased emissions.
Innovation Solution
The use of first and second locating pins extending from the valve housing, which are inserted into a locating bore to elastically deform and prevent rotational movement of the fuel injector, ensuring precise orientation and stable placement relative to the combustion chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a clearance fit is used between the fixation device and the recess, then manufacturing variations are accommodated, but rotational movement of the fuel injector is allowed
Solution Approach 1:
The patent introduces an intermediary mechanism (fixation device with engagement features) between the fuel injector and the recess that mediates the connection. This intermediary translates the clearance fit into a more precise orientational relationship by providing positive engagement features that limit rotation while still accommodating manufacturing variations through the clearance.
Solution Approach 2:
The patent changes the parameters of the fixation device by adding engagement features such as protrusions and corresponding recesses that convert the clearance fit relationship into a controlled interference fit relationship. This parameter change allows the system to maintain ease of manufacture while achieving the desired orientational precision.
2Adaptability or versatility
If the fuel injector is allowed to rotate about the nozzle body axis, then manufacturing variations are accommodated, but spray placement precision is reduced
Solution Approach 1:
The fixation device acts as an intermediary that mediates between the need for tolerance to manufacturing variations and the need for precise spray placement. The engagement features of the fixation device ensure that the nozzle body is held in a precise rotational orientation while still allowing for reasonable manufacturing variations.
Solution Approach 2:
The fixation device performs preliminary action by pre-establishing the correct rotational orientation of the fuel injector during assembly. This preliminary orientation ensures that the spray is correctly positioned in the combustion chamber before operation begins, preventing rotational drift during use.
3Ease of operation
If a fixation device with clearance fit is used, then assembly is simplified, but fuel efficiency is reduced due to suboptimal spray placement
Solution Approach 1:
The fixation device serves as an intermediary that maintains the simplicity of assembly while ensuring optimal spray placement for fuel efficiency. The engagement features provide automatic alignment and orientation during assembly, eliminating the need for complex alignment procedures while ensuring the spray is correctly positioned for optimal combustion.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution ensures positive orientation of the fuel injector, maximizing fuel efficiency, minimizing harmful exhaust emissions, and reducing variations in fuel placement, thereby enhancing combustion performance.
Implementation Method 1
a first locating pin and a second locating pin each extending from the valve housing, the first locating pin extending from a first locating pin fixed end which is fixed to the valve housing to a first locating pin free end and the second locating pin extending from a second locating pin fixed end which is fixed to the valve housing to a second locating pin free end, the first locating pin and the second locating pin collectively being configured to be inserted into a locating bore which elastically deforms the first locating pin and the second locating pin, thereby preventing rotational movement of the fuel injector about the nozzle body axis
Data Source
AI summary
A fuel injector includes a nozzle body configured to be inserted into a fuel injector receiving bore of the internal combustion engine along a nozzle body axis; a valve housing held in fixed relationship to the nozzle body; and a first locating pin and a second locating pin each extending from the valve housing. The first locating pin extends from a first locating pin fixed end which is fixed to the valve housing to a first locating pin free end. The second locating pin extends from a second locating pin fixed end which is fixed to the valve housing to a second locating pin free end. The first locating pin and the second locating pin elastically deform when inserted into the bore, thereby preventing rotational movement of the fuel injector about the nozzle body axis.