Fuel Injector Control Valve Support Area Wear Reduction

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Solution Overview

Problem

Existing common rail injectors experience high wear on the linear sealing edge due to high load when the control valve closes, leading to significant wear on the sealing line.

Innovation Solution

A support area is assigned to the approximately linear sealing edge of the control valve element, extending into the high-pressure area when closed, causing a rapid pressure drop and distributing the impact impulse more evenly, thereby reducing component stresses and minimizing wear over the injector's service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the control valve element is designed with a sealing line that corresponds to the guide diameter, then the control valve achieves pressure balance and can switch very high pressures, but the linear sealing edge experiences high load and significant wear

Engineering Contradiction:
Improvepressure switching capabilityVSAvoidservice life of sealing line
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The sealing function is segmented into two distinct areas: a linear sealing line for pressure balancing and a separate annular support area for load distribution. This segmentation allows each area to perform its specific function optimally without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealing functionality is extended from a one-dimensional linear sealing line to a two-dimensional structure by adding an annular support area. This dimensional extension distributes the impact impulse radially across a larger surface, reducing stress on the original sealing line.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Strength

If the support area extends into the high-pressure area, then the impact impulse is distributed more evenly and component stresses are reduced, but the pressure balance of the control valve element may be negatively influenced

Engineering Contradiction:
Improvecomponent stress distributionVSAvoidpressure balance
Core Design Contradiction:
StrengthVSStress or pressure

Solution Approach 1:

The support area is designed with specific geometric characteristics (annular shape with defined radial and axial dimensions) that allow it to provide structural support while maintaining the pressure balance required for control valve operation. The local geometry is optimized to achieve both strength and pressure balance.

Inventive Principle:
Principle #3Local quality

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 solution increases the stability of the control valve element, minimizing wear on the sealing line and maintaining the pressure-balanced characteristic of the injector, resulting in reduced component stress and extended service life.

Implementation Method 1

the impact impulse with which the control valve element impacts the control valve seat assigned to it is distributed more evenly in the control valve, in particular in the control valve element, and consequently leads to lower component stresses

Methodology Applied
Scientific EffectPressure distribution: Pressure Gradient

Implementation Method 2

cause a rapid drop in pressure in the control chamber of the injector, which in turn results in an opening movement of the injection valve element

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP2235354B1Fuel injector the control valve element of which comprises a support region
Publication Date: 2015.07.08 ROBERT BOSCH GMBH
  • EP2235354B1 patent drawingFigure 1
  • EP2235354B1 patent drawingFigure 2
  • EP2235354B1 patent drawingFigure 3

AI summary

The invention relates to an injector (1), in particular, a common-rail injector for injection of fuel into a combustion chamber of an internal combustion engine, with an injection valve element (11), adjustable between a closed position and an open position, controllable by means of a control valve (26), which has a control valve element (25), adjustable between a closed position and an open position by means of an actuator (27) which in the closed position is an at least almost pressure-equalised and which has a sealing line (34) which cooperates in a sealing manner in the closed position of the control valve element (25) with a control valve seat (28) and which is lifted off the control valve seat (28) in the open position and hence opens fuel flow from a high pressure region (37) to a low pressure region (9) of the injector (1). According to the invention, the control valve element (25) has a support region (40) extending over the sealing line (34) in a radial direction to the high pressure region (37).