Fuel Injection Nozzle Hole Orientation to Prevent Seat Damage
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Solution Overview
Problem
Laser drilling of fuel injection nozzles often results in damage to the opposite blind hole wall or seating area due to insufficient deactivation of the laser, leading to increased waste and potential functional impairment.
Innovation Solution
The method involves aligning the drilling axis of the laser to direct the spray hole towards an area adjacent to the seating region facing away from the nozzle tip, ensuring that the laser energy dissipates before hitting critical areas, and optionally angling the spray hole at least 45° to the nozzle's longitudinal axis to prevent damage during laser drilling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser drilling is used to create injection holes, then surface smoothness and manufacturing speed are improved, but the opposite wall or seating area may be damaged due to insufficient laser deactivation
Solution Approach 1:
The patent changes the spatial dimension by angling the injection hole drilling axis at 45-90 degrees relative to the nozzle longitudinal axis, rather than drilling perpendicular to the tip surface. This angular orientation ensures that when the laser penetrates through the tip wall, the beam exits toward the rear of the nozzle away from the seating area, preventing damage to critical functional surfaces while maintaining the advantages of laser drilling.
2Reliability
If the laser is deactivated quickly to prevent damage, then reliability is improved, but manufacturing precision may suffer due to incomplete hole penetration
Solution Approach 1:
By drilling at an angle of 45-90 degrees relative to the nozzle longitudinal axis, the patent creates a geometric configuration where the laser beam's path through the tip wall does not intersect the seating area. This angular approach allows the laser to be deactivated promptly after penetration without risking damage to the opposite wall, while still achieving complete hole formation through the tip thickness.
3Ease of manufacture
If the injection hole is drilled perpendicular to the tip surface, then manufacturing simplicity is improved, but the seating area is vulnerable to laser damage
Solution Approach 1:
The patent introduces asymmetry by drilling the injection hole at an angle of 45-90 degrees relative to the nozzle longitudinal axis rather than perpendicular to the tip surface. This asymmetric orientation redirects the laser beam's exit path away from the seating area, eliminating the harmful effect of laser-induced damage to critical surfaces while maintaining manufacturing feasibility.
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 approach prevents damage to functionally relevant areas, reduces nozzle waste, and allows for smoother surfaces, enhancing the reproducibility and performance of laser-drilled spray holes while maintaining the advantages of laser drilling over traditional erosion processes.
Implementation Method 1
it is known from the prior art to manufacture the very small bores of the injection holes using an erosion process... There have long been efforts to produce injection holes using laser drilling
Implementation Method 2
the injection holes, typically produced using an EDM process, are rounded hydro-erosively. In this process, an abrasive fluid containing grinding particles is pumped through the injection holes under high pressure
Data Source
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AI summary
The invention relates to a nozzle for injecting fuel, comprising an injection orifice in the region of a nozzle tip for conducting fuel out of the nozzle, and a receiving orifice for receiving a nozzle needle, wherein the receiving orifice comprises a seat region for sealingly engaging a nozzle needle, in order to allow a supply of fuel to the injection orifice according to a position of the nozzle needle. The invention is characterised in that the longitudinal axis of the injection orifice is oriented towards a region of the receiving orifice that adjoins the side of the seat region remote from the nozzle tip.