Fuel Injection Valve Split Annular Space Adhesion
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Solution Overview
Problem
Existing fuel injectors face challenges with high adhesive forces between the intermediate valve member and the intermediate part, which can lead to difficulties in precisely timing the termination of the injection process, and require complex and expensive manufacturing processes.
Innovation Solution
A fuel injection valve design featuring a needle-shaped injection valve member, a compression spring, and a mushroom-shaped intermediate valve member with a split annular space that minimizes adhesive forces and allows for precise control of the injection process, using a throttle passage and an annular sealing surface to optimize sealing and reduce adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the sealing surface of the head and the surface of the intermediate valve seat are designed to be inclined relative to each other to maintain a throttled fluid connection, then adhesion forces are reduced, but manufacturing precision requirements become exceptionally delicate and very expensive
Solution Approach 1:
The patent changes the geometric parameters of the sealing surfaces by introducing a specific inclination angle (alpha) between the sealing surface of the head and the intermediate valve seat surface. This parameter change creates a throttled fluid connection that reduces adhesion forces while maintaining seal integrity, resolving the contradiction between reducing harmful adhesion and avoiding excessive manufacturing precision requirements
Solution Approach 2:
The patent introduces a throttled fluid connection as an intermediary mechanism between the high-pressure inlet and the sliding fit. This intermediary maintains a controlled fluid path that prevents complete sealing, thereby reducing adhesion forces without requiring extremely precise manufacturing tolerances
2Reliability
If the high-pressure inlet is completely closed with full contact between sealing surfaces, then sealing is improved, but adhesive forces increase making it difficult to reopen the intermediate valve
Solution Approach 1:
The patent applies partial sealing action by designing the sealing surfaces to contact each other at an inclination, creating a throttled connection rather than complete closure. This partial sealing maintains sufficient seal reliability while preventing full adhesion that would make reopening difficult
Solution Approach 2:
By changing the contact parameter from full surface contact to inclined partial contact, the patent achieves a balance where sealing reliability is maintained through the inclined contact zone while the throttled fluid connection prevents excessive adhesion forces
3Productivity
If the cross-section of the outlet from the valve chamber is significantly larger than the throttle passage, then injection control is improved, but the opening movement of the injector element becomes dependent solely on the throttle passage cross-section
Solution Approach 1:
The patent segments the flow control into two distinct zones: a large-cross-section outlet from the valve chamber for high productivity injection control, and a precisely controlled throttle passage for regulating opening movement. This segmentation allows each zone to optimize its function independently
4Reliability
If an annular line seal is achieved between the valve element and valve seat, then sealing is improved, but the extreme manufacturing precision required makes the process very expensive
Solution Approach 1:
The patent changes the sealing parameter from requiring extreme precision in a flat annular line seal to using an inclined sealing surface configuration. This parameter change creates a throttled fluid connection that achieves sufficient sealing reliability through the inclination angle rather than through extreme dimensional precision
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
The design effectively reduces adhesive forces and allows for precise control of the injection process, enabling faster and more accurate termination of fuel injection while being cost-effective to manufacture.
Implementation Method 1
a compression spring, whose one end interacts with the injector element and whose other end is fixedly supported relative to the housing, exerts a closing force on the injection valve element in the direction towards the injection valve seat
Implementation Method 2
the sealing surface of the head and the surface of the intermediate valve seat are designed such that, in the closed position of the intermediate valve, they establish a throttled fluid connection between the high-pressure inlet and the sliding fit
Data Source
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AI summary
The fuel injection valve (10) comprises an intermediate valve with a mushroom-shaped intermediate valve member (78). The shaft (76) of the intermediate valve member (78) is guided with a sliding fit in the guiding passage (74) of an intermediate component (66). An annular space (120) is defined between the shaft (76) and the head (80) of the intermediate valve member (78) and the intermediate component (66), and a high-pressure inlet (86) opens into the annular space, which is formed by an inner annular space (108) and by a split ring space (118). The split ring space (118) is defined between the head (80) and the intermediate component (66), and is also radially outwardly defined by a sealing bead (112). The adhesion force between the intermediate valve member (78) and the intermediate component (66), which acts against the opening motion of the injection valve member (56), is minimised.