Balanced Metering Servovalve Deformable Ring Sealing
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Solution Overview
Problem
Existing fuel injectors with balanced metering servovalves for internal-combustion engines face challenges in producing precise fluid tightness, requiring complex machining operations and high costs due to the need for strict geometrical tolerances and multiple fluid-tight metal surfaces, which can lead to deformation and performance issues.
Innovation Solution
A fuel injector design featuring a metering servovalve with a deformable ring housed between two pieces, allowing for simpler production and reduced costs by using a perforated body that provides axial guidance and fluid tightness, while maintaining precise calibration through calibrated restrictions and elastic deformation for improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the valve body is made of three pieces (tubular guide body, distribution body, and disk) to enable assembly and calibration, then the calibrability and adaptability are improved, but the manufacturing complexity and cost increase due to requiring grinding operations on four fluid-tight metal surfaces
Solution Approach 1:
The patent merges the tubular guide body, distribution body, and disk into a single-piece valve body. This integration eliminates the interfaces between multiple components, removing the need for grinding operations on four fluid-tight metal surfaces while maintaining the calibrated portion for flow control. The single-piece construction simplifies manufacturing while preserving calibrability through the integrated calibrated portion.
2Adaptability or versatility
If the valve body is made of three pieces to allow calibration, then the adaptability is improved, but the manufacturing precision and time are worsened due to requiring strict geometrical tolerances and multiple grinding operations
Solution Approach 1:
The patent merges the tubular guide body, distribution body, and disk into a single-piece valve body. This integration eliminates the interfaces between multiple components, removing the need for grinding operations on four fluid-tight metal surfaces while maintaining the calibrated portion for flow control. The single-piece construction simplifies manufacturing while preserving calibrability through the integrated calibrated portion.
3Reliability
If the theoretical average diameter of fluid tightness between tubular guide body and disk is made large to ensure tightness, then the reliability is improved, but the axial forces increase causing deformations on the disk
Solution Approach 1:
The patent merges the tubular guide body, distribution body, and disk into a single-piece valve body, eliminating the interface between these components. This removes the source of axial forces that cause deformations while maintaining fluid tightness through the integrated structure. The calibrated portion is directly formed in the single-piece body, ensuring both tightness and structural integrity without deformation-related errors.
4Device complexity
If the valve body is made of a single piece to simplify production, then the device complexity is reduced, but the manufacturing precision is worsened due to requiring extremely high tolerances for the shaft of axial stem to coincide with the axis of blind hole
Solution Approach 1:
The patent merges the tubular guide body, distribution body, and disk into a single-piece valve body. This integration eliminates the interfaces between multiple components, removing the need for grinding operations on four fluid-tight metal surfaces while maintaining the calibrated portion for flow control. The single-piece construction simplifies manufacturing while preserving calibrability through the integrated calibrated portion.
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 design simplifies production, reduces costs, and maintains precise fluid tightness with reduced axial forces, ensuring consistent performance and preventing deformation-related errors, thus enhancing the dynamic behavior of the injector.
Implementation Method 1
a deformable ring housed in at least one between said first and second pieces
Implementation Method 2
a discharge channel, which is made in said first and second pieces and comprises at least one calibrated restriction
Data Source
AI summary
A fuel injector has an injector body and a control rod, which is movable in the injector body along an axis for controlling opening/closing of a nozzle that injects fuel in an engine cylinder; the injector body houses a metering servovalve, provided with a control chamber and with an open/close element of a balanced type, axial sliding of which causes a variation in pressure in the control chamber; the metering servovalve comprises a valve body made of two pieces coaxially coupled to one another via a deformable ring, which defines also a gasket for guaranteeing fluid tightness between the two pieces and maintains in a fixed position a disk on which a calibrated restriction is made.